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.
A student is worried about determining if a chemical is radioactive. Which
section of the SDS would the student refer to?
Product Information
Fire Fighting Methods
Physical and Chemical Properties
Hazards Identification
Answer:
Hazards Identification
Explanation:
A safety data sheet, SDS, is an informational document provided by the manufacturer or importer of a hazardous chemical detailing the chemical, physical, health, and environmental health hazards associated with the chemical as well as safety precautions in handling the chemical.
Some of the sections in the SDS include:
Product Information: It identifies the chemical as well as its recommended uses. The contact information of the manufacturer is also provided.
Fire fighting methods: It gives measures and guidelines necessary for fighting a fire caused by the chemical.
Physical and chemical properties: states the physical and chemical properties of the chemical substance such as: appearance, odor, pH, melting/freezing point, boiling point and boiling range, flammability, etc.
Hazards identification: states the hazards of the chemical and the necessary warnings regarding the hazards. Some of the information provided include: hazard classification of the chemical (for example flammable liquid, oxidizing gases,explosives, etc), signal word, hazard statement (for example radioactive), pictograms, precautionary statements, etc.
From the above information provided, the student should refer to the hazards identification section.
the density is 5.4 g/mL and the volume is 12.9 mL.
Answer:
69.66 g
Explanation:
We have the following from the question;
Density of the substance = 5.4 g/ml
Volume of substance = 12.9 ml
Mass of substance= the unknown
Since we have both density and volume of the substance, the question must be for us to obtain the mass of the substance, hence;
Density= mass/volume
Mass= Density × volume
Mass = 5.4 g/ml × 12.9 ml
Mass= 69.66 g
How is the Law of Conservation of Mass being followed in a voltaic cell with a zinc anode and a copper cathode? A. No mass is lost because electrons are flowing, not atoms. B. The mass lost by the copper electrode is gained by the zinc cathode. C. The Law of Conservation of Mass is not followed when electricity is generated. D. The mass lost by the zinc electrode is gained by the copper cathode.
Answer:
b
Explanation:
In the given scenario, the mass lost by the copper electrode is gained by the zinc cathode. The correct option is B.
What is Law of Conservation of Mass?The law of conservation of mass asserts that mass is neither created nor destroyed in a chemical reaction.
As electrons are lost at the anode, metal cations construct and dissipate into the solution, reducing the anode's mass through corrosion. The anode's lost electrons attract to the positively charged cathode and flow through the wire.
Thus, the correct option is B.
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Balance the following equation. Choose "blank" if no coefficient other than 1 is needed. CaCl2 + Na2CO3 CaCO3 + NaCl
Answer:
Hi there!!!
The answer is given in picture.
In question we had 2 sodium(Na) and chlorine (cl) but after reaction nacl donot contain it. so, we need to put 2 infront of nacl to make them equal.
As balancing chemical equation refers to the process of keeping or making equal to the atoms of both product and reactant.
Hope it helps..
differentiate between Physical and chemical changes
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)In a reversible reaction, the endothermic reaction absorbs ____________ the exothermic reaction releases.
A. None of these, endothermic reactions release energy
B. more energy than
C. the same amount of energy as
D. less energy than
Answer:
C. the same amount of energy as
Explanation:
Firstly, a chemical reaction can either absorb energy from its surroundings to occur or release energy into its surroundings as a product. The former and latter descriptions are called ENDOTHERMIC and EXOTHERMIC reactions respectively. An exothermic reaction is that which transfers energy, in form of heat, to its surroundings while an Endothermic reaction is that which absorbs energy (heat) from its surroundings.
However, a reversible reaction is that reaction in which the formation of products from reactants and reformation of the reactants from products occur simultaneously. Hence, the products of a reversible reaction can become the reactants and move in the opposite direction. For example:
Reversible reaction: A + B ⇆ C + D means;
A + B → C + D and;
C + D → A + B
In a case whereby the opposite reactions consist of an endothermic and exothermic reactions, the endothermic reaction absorbs the same amount of energy as the exothermic reaction releases.
According to the law of conservation of energy, no energy is lost during a reversible reaction. Hence, in order to achieve an equilibrium, the amount of energy absorbed by the endothermic reaction is the same as the amount of energy released in the opposite exothermic reaction.
Which statement best describes the destiny of an atoms nucleus?
Answer:
The answer would be: An atom’s nucleus occupies very little of the atom’s volume but contains most of its mass
Explanation:
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.
Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud.
Refer to https://en.wikipedia.org/wiki/Atomic_nucleus for further understanding
What type of Nuclear decay is shown by the reaction below
Answer:
bete is your answer.
have a great day.
I think c ....is write answers
What are the top three sources of US electricity generation?
The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources.
Write down the importance of nitrogen for plants
Explanation:
People also ask
What is the importance of nitrogen for plants?
Nitrogen is an essential macronutrient for plant function and is a key component of amino acids, which form the building blocks of plant proteins and enzymes. Proteins make up the structural materials of all living matters and enzymes facilitate the vast array of biochemical reactions within a plant.
Answer:
Nitrogen is vital because it is a major component of chlorophyll, the compound by which plants use sunlight energy to produce sugars from water and carbon dioxide(i.e.,photosynthesis). It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants wither and die.
I hope this helps.
For the set of ionic compounds, LiCl, AgCl, PbCl2, choose the correct characterization of their solubilities in water from the response list. Group of answer choices All three salts are soluble. None of the three salts are soluble. Two of the three salts are soluble. One of the three salts is soluble.
Answer:
Two of the three salts are soluble.
One of the three salts is soluble.
Explanation:
One or two of the three salts would be soluble in water depending on if the water is cold or hot.
According to the solubility rules of chloride salts, all chlorides are soluble in cold water except for those of silver (Ag), lead (Pb), and mercury (I) (Hg).
This thus means that both AgCl and [tex]PbCl_2[/tex] would be insoluble in cold water while LiCl would be soluble.
[tex]PbCl_2[/tex] is, however soluble in hot water.
Hence, in cold water, one of the three salts (LiCl) would be soluble, while in hot water, two of the three salts (LiCl and [tex]PbCl_2[/tex]) would be soluble.
Question 5: thanks you
Answer:
A linear molecule has a bond angle of 180°
a sample of element X contains 90% X-35 atoms,8.0%X-37 atoms, and 2.0% X-38 atoms. The average atomic mass will be closest to which value?
Answer:
35.2.
Explanation
R.A.M= Mass of isotopes divide by 100 percent
Was is meant by the term suprenatural? Does science deal with the supernatural?
A. The term supernatural literally means (within nature) Science deals with the supernatural because it works within nature, not above it
B. The term supernatural literally means (above nature) Science does not deal with the supernatural because it works within nature, not above it
C. The term supernatural literally means (within nature) Science does not deal with the supernatural because it works above nature, not within it
D. The term supernatural literally means (above nature) Science deals with the supernatural because it also works with nature, not within it
Answer:
The term supernatural literally means, Science does not deal with the supernatural because within nature, not within it
Question number 4..
Answer:
I think it's 7089 because that's my answer to your questions
Calculate the heat when 100.0 mL of 0.500 M HCl is mixed with 300.0 mL of 0.100 M Ba(OH)2. Assuming that the temperature of both solutions was initially 25.0C and that the final mixture has a mass of 400.0 g and a specific heat capacity of 4.18 J/C g, calculate the final temperature of the mixture.
Answer:
26.8°C
Explanation:
For this reaction, the equation can be computed as follows:
[tex]2HCl_{(aq)}+ Ba (OH)_{2(aq)} \to BaCl_{2(aq)} + 2H_2O_{(l)} \ \ \ \ \ \ \Delta H= -118 \ kJ[/tex]
Now, Given that:
100.0 mL of 0.500 molarity (M) of HCl reacted with 300.0 mL of 0.100 molarity of Ba(OH)2.
The next process is to determine the number of moles of the solute:
For HCl:
no of mole = [tex]\dfrac{0.500 \times 100}{1000}[/tex]
= 0.05 mol
For Ba(OH)2:
no of mole =[tex]\dfrac{0.100\times 300}{1000}[/tex]
= 0.03 mol
From the reaction, at the reactant side, we will see that two moles of HCl reacted with one mole of Ba(OH)2.
It implies that HCl is the limiting agent since it is in lesser quantity.
Similarly, the heat given out of the system is 118 kJ for each two moles of HCl with one mole of B(OH)2.
Hence, for 0.05 moles of HCl, the heat emitted out is:
[tex]= 0.05 mole \times ( \dfrac{118 \ kJ}{2 \mol})[/tex]
= 2.95 kJ
Let's recall from the question that:
the heat emitted was moved to the final mixture with mass =400g
the specific heat capacity = 4.18 J/°C g
Initial temperature = 25°C
∴
Using the formula;
ΔH = mass × specific heat capacity × (T_f - T_i)
Then, replacing the values, we have:
2.95 kJ = 400 g × 4.18 J/°C g × ( T_f - 25° C)
2950 J = 400 × 4.18 J/°C × ( T_f - 25° C)
[tex]T_f = \dfrac{2950 \ J}{400 \times 4.18 \ J/^0 C}+25^0\ C[/tex]
[tex]\mathbf{ T_f = 26.8^0 \ C}[/tex]
7.95x10 converted to the number is
7.95 × 10
= 79.5
This is the answer
HELP URGENT PLS!1!! In what direction and how many spaces must you move the decimal point to make the following conversion?
600 L to mL
left; 6 spaces
left; 6 spaces
left; 3 spaces
left; 3 spaces
right; 6 spaces
right; 6 spaces
right; 3 spaces
To convert from L to ml, we move three spaces to the right and the decimal place moves three places.
Our task here is to convert 600 L to mL. we have to remember that to convert from L to ml, we have to multiply the value in L by 1000
In other words, the value 1000 is known as the conversion factor.
When we do this, we move the decimal place three places to the right to have 600000.00mL
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Which bond type is found in ammonium chloride. Select one: a. metallic b. covalent c. ionic
Answer:
ionic
Explanation:
In NH4Cl molecule, ionic bond is formed between NH4+ and Cl– ions, 3 covalent bonds are formed between N and three H atoms and one coordinate bond is formed between N and 1 H atom.
HOPE IT HELPS :)
PLEASE MARK IT THE BRAINLIEST!
Answer:
[tex]\boxed{\sf c. \ ionic}[/tex]
Explanation:
NH₄Cl is formed by an ionic bond between NH₄⁺ and Cl⁻ ions.
NH₄Cl (solid) ⇒ NH4⁺ (aqueous) + Cl⁻ (aqueous)
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple ball in the center surrounded by overlapping concentric black ovals, each with a small green ball on each of the 6 ovals. What experimental evidence led to the development of this atomic model from the one before it? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
A few of the positive particles aimed at a gold foil seemed to bounce back.
Explanation:
Rutherford's experiment took the search for the structure of the atom a step further. In this experiment, a narrow beam of alpha particles emitted from a source was used to bombard a thin gold foil.
The scattering of the alpha particles was detected by a movable ZnS screen. It was found that most of the alpha particles followed a straight path through the gold foil but some were scattered through large angles and some even scattered backwards.
Following this experiment, Rutherford decided on his planetary model of the atom in which the nucleus is at the core of the atom with electrons moving round the nucleus in orbits. Rutherford was awarded a Nobel prize for this work.
Answer:
a
Explanation:
edge 2020
Atoms contain positive and negative charges. Why is the overall charge on an atom neutral?
A. Atoms contain the same amount of protons and electrons, and their charges cancel out.
B. The nucleus of an atom contains neutrons, which keep the positive and negative charges balanced.
C. Atoms are all negatively charged because electrons are on the outside of the atom.
D. Atoms contain the same amount protons and neutrons, and their charges cancel out.
Answer:
Atoms contain the same amount protons and neutrons, and their charges cancel out.
Explanation:
Answer via Educere/ Founder's Education
Atoms contain positive and negative charges, the overall charge on an atom neutral because Atoms contain the same amount of protons and electrons, and their charges cancel out.Hence, Option (A) is correct
What is an Atom ?
An atom is the smallest unit of ordinary matter that forms a chemical element.
Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms.
Atoms are extremely small, typically around 100 picometers across.
An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons.
The positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral.Hence, Option (A) is correct
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2 Write the molecular formula of the compounds given below: Sodium hydrogen carbonate b) calcium hydroxide ) silver nitrate d) ammonium sulphate ) Magnesium carbonate f) Ferric oxidea
[tex]\\ \rm\Rrightarrow Sodium\:Hydrogen\:carbonate=NaHCO_3[/tex]
[tex]\\ \rm\Rrightarrow Calcium\:Hydroxide=Ca(OH)_2[/tex]
[tex]\\ \rm\Rrightarrow Silver\:Nitrate=Ag(NO_3)_2[/tex]
[tex]\\ \rm\Rrightarrow Ammonium\:Sulphate=(NH_4)_2SO_4[/tex]
[tex]\\ \rm\Rrightarrow Ferric\:oxide=Fe_2O_3[/tex]
Can a window pane be considered a mineral?
Answer:
Explanation:
The glass (which does not crystallize even though it is accepted) of a window is NOT a mineral, since it is neither a substance of natural origin (although it is manufactured from natural components) nor does it have a defined crystalline structure, that is, the atoms they are not arranged in an orderly and regular way along axes and planes forming flat faces that keep a symmetry.
Remember that a mineral is defined as a solid, inorganic, homogeneous substance, of natural origin, with a crystalline structure and a determined and well-defined chemical composition within narrow margins and that has regular and characteristic physical properties.
Explanation: No, glass is not a mineral. ... Definable chemical composition: SiO2 *Actually, most industrially-produced glass is not pure silica, but having impurities is still a definable chemical composition so this part of the definition is ok. Orderly arrangement of atoms in a lattice: NO.
What are the standard temperature and pressure conditions enthalpy is usually measured under
Answer:
temperature must be 273 Kelvin (0°C)
pressure must be 1 atm
What orbits around the nucleus
Answer:
Electrons orbit the nucleus.
Answer:
electrons
Explanation:Atoms are made up of protons and neutrons located within the nucleus, with electrons in orbitals surrounding the nucleus.
Which of these factors will cause a solid solute to dissolve faster?
Answer:
Heat
Explanation:
Higher temperatures cause solid solutes to dissolve at a faster rate than normal
Answer:
Higher temperature
Explanation:
in the symbol 3p4
a. the 3 represents the principal energy level
b. the p represents the principal energy level
c. the 4 represents the principal energy level
d. all of the above
help!
Answer:
a. the 3 represents the principal energy level
Explanation:
3 is the principal energy level. The p is the sublevel. 4 is the possible occupying electron.
Use Charles's Law to solve the following problem. A sample of air has a volume of 550.0 mL at 106 °C. At what temperature will its volume be 700.0 mL at constant pressure?
a
482 K
b
63 °C
c
505 K
d
119 °C
Answer:
im not sure but i think its c
505 K
Please help...
Draw a diagram showing the bonding in:
a) Tetrachloromethane [CCI4]
Answer:
here u go! ................
Answer:
Hope this is ok :))
Explanation:
If an atom has three shell and number of valence electrons are two. Is this element metal
or non-metal and why? Name the element and it’s valency.
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.