Answer:
4.30 × 10²⁰ atoms
Explanation:
You need to find out how many moles you have. First, convert milligrams to grams.
62.5 mg × (1 g)/(1000 mg) = 0.0625 g
Next, use the molar mass to convert from grams to moles.
0.0625 g ÷ 87.62 g/mol = 7.13 × 10⁻⁴ mol
To convert from moles to atoms, you need to use Avogadro's number (6.022 × 10²³). Avogadro's number is the number of atoms in a mole.
7.13 × 10⁻⁴ mol × 6.022 × 10²³ atoms/mol = 4.296 × 10²⁰ ≈ 4.30 × 10²⁰ atoms
You will have 4.30 × 10²⁰ atoms of strontium.
The number of Strontium atoms are 4.30 × 10²⁰ atoms
Given:
Mass of Strontium = 62.5 mg × (1 g)/(1000 mg) = 0.0625 g
Molar mass of Strontium = 87.62 g/mol
To find:
Moles of Strontium = ?
Number of moles:It is defined as given mass over molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\\\\\text{Number of moles}=\frac{0.0625 g}{87.62 g/mol }\\\\\text{Number of moles}=7.13 * 10^{-4} mol[/tex]
Avogadro's number is the number of atoms in a mole (6.022 * 10²³)
Conversion of moles into atoms:
[tex]7.13 × 10^{-4} mol * 6.022 * 10^{23} atoms/mol \\\\\text{ Sr atoms}= 4.296 * 10^{20} = 4.30 * 10^{20} atoms[/tex]
Thus, Strontium atoms will be 4.30 × 10²⁰ atoms.
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Which of the following is NOT the property of a non-metal? A. Non-rigid structure B. Not ductile C. Low density D. Malleable
Answer:
The answer is D.
Explanation:
Malleable is the property of metal not non-metal.
Answer:
malleable
Explanation:
because a non metal cannot be harmmed into sheetswhich state of matter is Na OH(s)
Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
What is the complete ionic equation for this reaction?
2KOH(aq) + H2SO4(aq) → 2H20(1) + K2SO4(aq)
O A. 2K+ + OH + H2SO4 → OH + 2H+ + K2SO4
B. OH + 2H+ + 2H20()
C. 2KOH + H2SO4 → 2H20 + K2SO4
D. 2K+ + OH + 2H+ + SO42- → 2H20() + 2K+ + SO42-
SUBMIT
Answer:
The answer is "Option D".
Explanation:
The entire ionic equation for all the substances, which are ionic compounds but are available in an aquatic is represented in the form with ions in the full ionic equation.
In the Net ionic equation, it doesn't have the particulate matter throughout the net ionic equations throughout the equations.
In the Spectator ions, it doesn't participate in interactions mostly on reaction and the material hand. From both sides, the very same ions are present.
The evenly balanced chemical formula is,
[tex]2KOH (aq)+ H_2SO_4(aq) \longrightarrow 2H_2O(l) + K_2SO_4[/tex]
It is the separate organic compound that full ion formula will match the choice D.
What is the order, plz answer
Answer:
C A B
Explanation:
come on, you also know this from normal water waves.
which ones are stronger (= have more energy) ? the small ones or the big ones ?
and the same applies to all waves. the bigger the waves (higher amplitude), the more energy.
Match the set of measurements of the boiling point of water with the best
description.
Measurements
Description
6. 103 °C, 90 °C, 101 °C
a.
Precise
7. 100 °C, 99 °C, 100 °C
b.
Accurate
8. 105 °C, 106 °C, 105 °C
c. Both accurate and precise
9. 99 °C, 101 °C, 100 °C
d. Neither accurate nor precise
Answer:
Matching
6.D
7.A
8.C
9.B
Explanation:
Took test
103 °C, 90 °C, 101 °C Neither accurate nor precise, 100 °C, 99 °C, 100 °C are Precise, 105 °C, 106 °C, 105 °C are Both accurate and precise, 99 °C, 101 °C, 100 °C are Accurate. These are the correct set of measurements of the boiling point of water.
what are boiling point and melting point ?The melting point is defined as the temperature at which solid and liquid phases are at equilibrium state, whereas the boiling point is defined as the temperature at which the pressure of a vapor of a liquid is equal to the external pressure.
Melting point in which the melting of solid occur to become a liquid at a given temperature, here the molecules gain enough amount of kinetic energy to get the intermolecular forces to convert into another form.
In case of Boiling point the liquid phase enters into the gaseous phase, when the external pressure is high than a temperature for the vapor pressure equal to the external pressure.
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Solids have_____
density and_____
compressibility compared to
liquids.
Answer:
higher density and lower compressibility
Ethane- (-89) Butane- (0) Methanol- (64.7) Hexane- (69) Pentadecane- (270) Heptadecane- (302) a) A mixture of pendtadecane and heptadecane can be separated by______ b) Which pair of compounds are easiest to separate (i) Ethane and Pentadecane (ii) Ethane and Heptadecane (iii) Butane and Hexane (iv) Butane and Heptadecane
Answer:
(ii) Ethane and Heptadecane
Explanation:
The separation of all the species listed in the answer options for the question depends on the molar mass of each specie.
Ethane is a low molecular mass gas. It exists in the gaseous state at room temperature. However, heptadecane appears as a liquid because it has a greater relative molecular mass.
It is very easily to distinguish between the gas, ethane and the liquid heptadecane which is a high molecular mass alkane, hence the answer.
Balance
Mg +O2
NH3+ H2SO4
H20+O2
Answer:
MgO2
H202
NH4)2SO4
Explanation:
hope this helps you
Which of the following is an example of combustion?
O A. potassium chlorate -> potassium chloride + oxygen
B. aluminum + cobalt chloride -> aluminum chloride + cobalt
O c. hexane + oxygen carbon dioxide + water
OD. sodium cyanide + hydrochloric acid -> sodium sulfate + hydrogen cyanide
Sulphur dioxide is a common pollutant from burning coal.State two effects caused by this pollutant and also write the chemical equation.
Heya!
Sulfur dioxide - ( SO2 )
Answer:
Sulfur dioxide is a common pollutant caused due to the burning of coal,Is very harmful for the environment and health.Effects:
Health effects-Sulfur dioxide effects the respiratory system which includes the functioning of lungs,respiratory track and causes infections,can also effect and irritate the eyes and causes aggravating conditions such as asthma and chronic bronchitis.As most sulfur dioxide air pollution comes from the burning of coal and oil in power plants. It is a emitted by trains, large ships and other diesel objects that burns alota sulfur fuel so this also effects the environment like plants and others as the air lacks oxygen ,but with more sulfur dioxide.Hope this helps!
Have a nice day!:)
calculate the pH of 500cm3 of 0.2mol/dm3 Ca(OH2), assume complete ionisation
Answer:
The pH of 500 cm³, 0.2 mol/dm³, Ca(OH₂) is ≈ 13.6
Explanation:
The given parameters are;
Concentration of the calcium hydroxide, Ca(OH₂) = 0.2 mol/dm³
Volume of the calcium hydroxide, Ca(OH₂) = 500 cm³
Given that the calcium hydroxide, Ca(OH₂), undergoes complete ionization in water, complete dissociation, we have;
Ca(OH₂) ⇄ Ca²⁺ + 2 OH⁻
Therefore, we have;
2 moles of [OH⁻] for each mole of Ca(OH₂) which gives the concentration of [OH⁻] as
[OH⁻] = 2 × 0.2 ≈ 0.4 mol/dm³
The pH is given by the formula
pH = 14 + ㏒₁₀ [OH⁻]
pH = 14 + ㏒₁₀ (0.4) = 14 - 0.3979 = 13.6021 ≈ 13.6
The pH of the 500 cm³ 0.2 mol/dm³ Ca(OH₂) ≈ 13.6.
CH4 + 2O2 → CO2 + 2H2O In the chemical reaction, if 10 moles of H2O are produced, moles of CO2 are also produced
Answer:
The correct answer is 5 moles of CO2 are produced.
Explanation:
The given reaction:
CH₄ (g) + 2O₂ (g) ⇔ CO₂ (g) + 2H₂O (g)
The given reaction is an illustration of a combustion reaction. Any reaction in which a substance is burnt in excess of oxygen to generate water and carbon dioxide is termed as a combustion reaction. From the given equation, it is clear that the moles of the formation of the products are in the ratio 1: 2, that is, if 10 moles of H₂O is produced, the production of 5 moles of CO₂ will be produced.
Let us multiply, the given equation with 5 we get,
5CH₄ + 10O₂ ⇔ 5CO₂ + 10H₂O
Hence, it is clear that with the formation of 10 moles of H₂O, formation of 5 moles of CO₂ will also take place.
Which element increases its oxidation number in this reaction? 3KOH + H3PO4 → K3PO4 + 3H2O
Answer:
The answer is "no changes in oxidation number "
Explanation:
Given equation:
[tex]3KOH + H_3PO_4 \longrightarrow K_3PO_4 + 3H_2O[/tex]
In the above-given equation, there are no changes in the oxidation number which can be defined as follows but first we defined the oxidation: In the chemical process, it requires the transfer of ions is oxidation. In particular, it means that products that supply electrodes are oxidized. In the given equation, when 3Potassium hydroxide reacts with phosphoric acid it will produce potassium phosphate and 3 moles of water.
Ou Esaplain different form
of oxygen?
Answer:
oxygen is the chemical element with the atomic number is 8 and the symbol is o its known as called oxygen.
Explanation:
Oxygen is the most third element in the universe at they standard and temperature and pressure,and oxides most elements as other compounds.
Oxygen gas is the earth atmosphere is 21%, an oxygen is the half of the earth crust in form of oxide,oxygen is liquid and solid gas.
Oxygen atoms such as proteins and acids, fats the major organic compounds, oxygen as component of the water and carbon dioxide.
Oxygen has many characteristics :- properties and molecular structure:-
this is a pressure and temperature with molecular formula referred as oxygen,simply describe a double bond and molecular orbits.
Physical properties:- oxygen is highly substance and must be combustible materials, oxygen may also from using a liquid nitrogen coolant, molecular oxygen is the associated with the process of air glow.
Stellar origin :- all of the remaining to half lives to the majority of are less then milliseconds.
Occurrence:- oxygen is the process part of the element in the earth crust, free oxygen is also occurs in the world bodies.
Analysis :- analysis to the structure of vegetation and the carbon cycle on a global scale.
PLZ HELP ME A single bacterial cell divides to make new bacterial cells. Which of the following is true of this kind of reproduction? A Two parents come together to produce offspring with different characteristics
B. Two parents come together to produce offspring that are exact copies of one parent
C One parent produces offspring that are exact copies of the parent
D. One parent produces of sening with different charactenstes SUERT
Answer:
its C
Explanation:
[tex]v=0.164m*8.3cm*12.4cm[/tex]
Answer:
helloooo
0.164m * 100 = 16.4 cm
now multiplying all of em
v = 1,687.888
HCL is pure covalent compound but soluble in solvent water why
Answer:
HCl is a polar covalent compound, because of electronegativity difference between Cl(3.5) and hydrogen (2). Hence in this way, the bond between HCl breaks and they formed ions in the polar solvent like water .
Match the chemical equation with the correct reaction type:
Column A
Column B
1.
Fe +52 - Fe253
2.
Pb(NO3)2 + K2CrO 4 PbCrO 4 +KNO3
a. single replacement
b. double replacement
C. decomposition
3.
H2 + N2 + NH3
d. combustion
4.
Fe + CuCl2 - FeCl2 + Cu
e synthesis
5.
KCIO3 -KCI + O2
6.
Mg + HCI-H2 + MgCl2
7.
C3Hg + O2 CO2 + H2O
8.
Zn + HCI - ZnCl2 + H2
9.
NH3-N2 + O2
10.
AgNO3 + Cu Cu(NO3)2 + Ag
f70X
1.
Fe +52 - Fe253
SYNTHESIS REACTION
A synthesis reaction occurs when two or more reactants combine to form a single product.
2.
Pb(NO3)2 + K2CrO 4 PbCrO 4 +KNO3
DOUBLE REPLACEMENT
A double-replacement reaction exchanges the cations (or the anions) of two ionic compounds.
3.
H2 + N2 + NH3
SYNTHESIS REACTION
A synthesis reaction occurs when two or more reactants combine to form a single product.
4.
Fe + CuCl2 - FeCl2 + Cu
SINGLE REPLACEMENT
A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound.
Note. An element can only replace an element that it is higher than in the electrochemical series or an element that is less reactive than itself.
5.
KCIO3 -KCI + O2
DECOMPOSITION REACTION
A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances.
Most times this type of reaction requires an in put of energy.
It is usually an endothermic reaction as heat is mostly absorbed.
6.
Mg + HCI-H2 + MgCl2
SINGLE REPLACEMENT
A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound.
Note. An element can only replace an element that it is higher than in the electrochemical series or an element that is less reactive than itself.
7.
C3Hg + O2 CO2 + H2O
COMBUSTION REACTION
Combustion reaction is a high-temperature exothermic redox chemical reaction between a fuel (example propane C3H8) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products.( mostly C02)
It can also be referred to as burning.
Combustion reaction is one of the chemical characteristics of hydrocarbons.
8.
Zn + HCI - ZnCl2 + H2
SINGLE REPLACEMENT
A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound.
Note. An element can only replace an element that it is higher than in the electrochemical series or an element that is less reactive than itself.
9.
NH3-N2 + O2
DECOMPOSITION REACTION
A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances.
Most times this type of reaction requires an in put of energy.
It is usually an endothermic reaction as heat is mostly absorbed.
10.
AgNO3 + Cu Cu(NO3)2 + Ag
f70X
SINGLE REPLACEMENT
A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound.
Note. An element can only replace an element that it is higher than in the electrochemical series or an element that is less reactive than itself.
Which best describes the importance of the microscope to the development of the cell theory?
Answer:
The answer is "all the cells are too small, which is not seen by the naked eye, that's why we use a microscope to see it".
Explanation:
In the given question the choices were missing so, we define the correct answer only.
Cells are the essential building blocks of all living entities. There will be trillions of cells within the body. They construct a body shape, absorb nutrients, transform them into energy, and conduct specialized features.
It provides stability and guidance, encourages mitotic cell development, encourages active and passive transfer, generates energy, induces metabolic processes, and contraceptive support.
What information does the specific heat capacity give about a substance?
A. How much energy is needed to raise its temperature
B. How much heat is released when it changes phases
C. How much energy is needed to overcome an activation energy
O
0
D. How much heat is stored in its chemical bonds
Specific heat capacity tells about how much energy is needed to raise its temperature.
What is specific heat capacity?
Specific heat capacity is defined as the amount of energy required to raise the temperature of one gram of substance by one degree Celsius. It has units of calories or joules per gram per degree Celsius.
It varies with temperature and is different for each state of matter. Water in the liquid form has the highest specific heat capacity among all common substances .Specific heat capacity of a substance is infinite as it undergoes phase transition ,it is highest for gases and can rise if the gas is allowed to expand.
It is given by the formula ,
Q=mcΔT
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what is mean by vector
Answer:
A quantity having direction as well as magnitude is called vector.
what are two consents in this experiment
The number of cricket chirps
The temperature of each container
The kind of containers used
The number of crickets in each container
Answer:
the number of crickets in each container
Explanation:
to participate in the experiment you will have to know the crickets in the container
In 1838 botanist Matthias Schleiden determined that all plants are composed of cells. In 1839, anatomist Theodor Schwann proposed that all animals are composed of cells. In 1855, biologist Rudolph Virchow added to Schleiden's and Schwann's observations and proposed that all living things are composed of cells. Which statement is also part of Virchow's cell theory?
Answer:
cells arose from preexisting cells
Explanation:
Rudolph Virchow is a German biologist that built on the work of other scientists such as Theodor Schwan to contribute his own quota to the development of the cell theory as it is currently known.
After several studies, Virchow rejected the idea of spontaneous generation and accepted the initially rejected idea of cell division. He earlier believed that cell division only takes place is some special type of cells and not in all cells.
Even though Virchow was not the first to bring the idea of cells arising from preexisting cells, he was the one that popularized the idea and added it to the earlier belief that all living organisms are made up of cells.
Answer:
B
Explanation:
write the formula of three compounds which you know and name the elements in them
Answer:
[tex]\boxed{\sf{view \ explanation}}[/tex]
Explanation:
Compound definition:
A compound is a chemical substance formed by two or more chemically bonded elements.
Three compounds:
Water is a compound with the formula [tex]\sf H_2O[/tex].
Two hydrogen atoms and one oxygen atom is present in one molecule of water.
Sodium chloride or table salt is a compound with the formula [tex]\sf NaCl[/tex].
One sodium atom and one chlorine atom is present in one molecule of sodium chloride.
Ammonia is a compound with the formula [tex]\sf NH_3[/tex].
In one molecule of ammonia, one nitrogen atom and three hydrogen atoms are present.
Answer:
See below
Explanation:
Three compounds are:
1) [tex]\mathrm {H_{2}SO{4}}[/tex] [Sulfuric acid]
The elements in this compound are hydrogen (H) , Sulfur (S) and Oxygen (O).
2) [tex]\mathrm {NaOH}[/tex] [Sodium hydroxide]
The elements in this compound are Sodium (Na) , Oxygen (O) and Hydrogen (H).
3) [tex]\mathrm {HCl}[/tex] [Hydrochloric acid]
The elements are Hydrogen (H) and Chlorine (Cl).
Convert 16.7 inches to yards (there are 3 feet in a yard)
Using the method of dimensional analysis
Answer:
Explanation:
16.7 inches [1 foot / 12 inches] [1 yard / 3 feet] Notice how the units cancel each other out. You do have numbers in the denominator. What you get, looks like this
16.7
------
(12 * 3)
16.7 / 36
0.4639 yrds
The melting points of ionic compounds _____
Explanation:
ionic compounds have high melting points
Which is not a characteristic of all metals? Select one: a. soft and easy to cut b. Good electrical conductors c. Ductile and malleable
If 25.0 g of carbon monoxide react with 8.50 g of ammonia and 10.0 g of hydrogen to produce water and acetonitrile (CH3CN), what mass of each excess reactant is left over after the reaction is complete?
Answer:
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂
Explanation:
The given information are;
The mass of the carbon monoxide present in the reaction = 25.0 g
The mass of the ammonia present in the reaction = 8.50 g
The mass of the hydrogen present in the reaction = 10.0 g
The above masses reacts to produce water and acetonitrile (CH₃CN)
The balanced chemical equation for the reaction is given as follows;
2CO + NH₃ + 2H₂ → CH₃CN + 2H₂O
Therefore, two moles of CO reacts with one mole of NH₃ and two moles of H₂ to produce one mole of CH₃CN and two moles of H₂O
The molar mass of CO = 28.01 g/mol
The molar mass of NH₃ = 17.031 g/mol
The molar mass of H₂ = 2.0159 g/mol
The molar mass of H₂O = 18.015 g/mol
The molar mass of CH₃CN = 41.05 g/mol
The number of moles of CO present = 25/28.01 = 0.893 moles
The number of moles of NH₃ present = 8.5/17.031 = 0.5 moles
The number of moles of H₂ present = 10/2.0159 = 4.96 moles
Therefore, 0.893 moles of CO reacts with 0.893/2 mole of NH₃ and 0.893 moles of H₂ to produce 0.893/2 mole of CH₃CN and 0.893 moles of H₂O
The excess reactants left are;
0.5 - 0.893/2 = 0.0535 moles of NH₃ with mass 0.0535 × 17.031 = 0.91 g
4.96 - 0.893 = 4.067 moles of H₂ with mass 4.067 × 2.0159 = 8.2 g
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂.
For the set of ionic compounds, CaSO4, CaCO3, Ca(OH)2, choose the correct characterization of their solubilities in water from the response list. Group of answer choices None of the three salts are soluble. All three salts are soluble. Two of the three salts are soluble. One of the three salts is soluble.
Answer:
None of the three salts are soluble.
Explanation:
According to the solubility rule, the carbonates and sulphates of group two elements are insoluble in water.
All three substances mentioned possess very low solubility in water and can be said to be slightly soluble in water. If we compare them with other ionic substances that dissolve readily in water, we can rightly say that they are insoluble in water.
Hence all three substances are insoluble in water.
Se someten a combustion 0,452g de un compuesto de C,H y N de masa molecular 80. Al recoger el CO2 y el H2O producidas obtenemos 0,994 g y 0,203 respectivamente. Determine formula empirica y formula molecular
Answer:
Fórmula empírica: C₂H₂N
Fórmula molecular: C₄H₄N₂
Explanation:
Un compuesto que contiene carbono hidrógeno y nitrógeno con fórmula CₐHₓNₙ es sometido a combustion produciendo:
CₐHₓNₙ + O₂ → aCO₂ + x/2 H₂O + nNO₂
Con la masa de dióxido de carbono y agua podemos encontrar las moles de carbono e hidrógeno y su aporte a los 0.452g de muestra que fueron puestos en combustión, así:
Moles C:
Moles C = Moles CO₂ = 0.994g CO₂ ₓ (1mol / 44g) = 0.0226 moles C
Masa C: 0.0226 moles C ₓ (12.01g / mol) = 0.271g Carbono hay en la muestra
Moles H:
Moles H = 2 Moles H₂O = 0.203g H₂O ₓ (1mol / 18g) = 0.0113 moles H₂O = 0.0226 moles H
Masa H: 0.0226 moles H ₓ (1.01g / mol) = 0.023g Hidrógeno hay en la muestra
Así, la masa de nitrógeno en la muestra y sus moles son:
Masa N = 0.452g - 0.271g C - 0.023g H
Masa N = 0.158g Nitrógeno
Y su moles son:
0.158g ₓ (1 mol / 14.01g) = 0.0113 moles N
Con las moles de C, H y N podemos determinar la formula empírica que se define como: "La relación de números enteros más simple entre la cantidad de átomos presentes en una mólecula. Si usamos como base las moles de nitrógeno (Valor menor):
Relación H/N: 0.0226 mol / 0.0113 mol = 2
Relación C/N: 0.0226 mol / 0.0113 mol = 2
Relación N/N: 0.0113 mol / 0.0113 mol = 1
Así, la fórmula empírica es:
C₂H₂NEsta fórmula empírica tiene una masa molar de:
2C = 2*12 g/mol = 24g/mol
2H = 2*1g/mol = 2g/mol
N = 14g/mol
24+14+2 = 40g/mol
Como la masa molecular del compuesto es 80g/mol (Dos veces la de la fórmula empírica, la fórmula molecular es 2 veces la fórmula empírica:
C₄H₄N₂