Answer:
1.Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.
2.The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observations.
3.0 cm x 4.0 cm x 1.0 cm
[?]cm^3
Explanation:
Hi there!!
you asked to multiply these all right,
you can simply multiply it ,
=3cm × 4 cm × 1cm
= 12cm^2×1cm (4×3=12)
= 12cm^3 (12×1=12)
Therefore, theanswer is 12 cm^3.
Hope it helps..
how to unscramble dtneinreigs
Answer:
Ingredients OR tenderising
Explanation:
The unit of force newton is a derived unit.Why?
Answer:
Why is the unit of force called a derived unit? That's because the Newton is defined in terms of other units which are more fundamental. One Newton is the force required to accelerate a mass of one kilogramme at the rate of one metre per second squared.
What is known about a reaction with a positive enthalpy?
Answer:
"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."
Explanation:
When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.
What does a high positive enthalpy mean?
The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.
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A 50.51 g sample of a compound made from phosphorus and chlorine is decomposed. Analysis of
the products showed that 11.39 g of phosphorus atoms were produced. What is the empirical formula
of the compound?
Answer:
pcl3 is the empirical formula of the compound
Water and development are substitute of one another?
explanation with it, please
Due to common purpose water and development are substitute of one another.
Water and development are substitute of one another because both contribute in the growth of economy of a country and increases life standard of its people. The presence of water causes growth and betterment of the economy that leads to development of the nation so we can say that due to same effect, both are used as a substitute i.e. in place of one another in the process of growth and betterment.
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Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH)2 (s) In a particular experiment, a 2.00-g sample of CaO is reacted with excess water and 2.14 g of Ca(OH)2 is recovered. What is the percent yield in this experiment? a. 107 b. 1.07 c. 2.88 d. 81.1 e. 93.3
Answer:
The option closest to the percentage yield is option;
d. 81.1
Explanation:
The given chemical equation of the reaction is presented as follows;
CaO (s) + H₂O (l) → Ca(OH)₂
The mass of CaO in the experiment, m = 2.00 g
The volume of water with which the CaO was reacted = Excess volume of water
Number of moles = Mass/(Molar mass)
The mass of Ca(OH)₂ recovered, actual yield = 2.14 g
The molar mass of CaO = 56.0774 g/mol
The number of moles of CaO in the reaction, n₁ = 2.00 g/(56.0774 g/mol ≈ 0.036 moles
The molar mass of Ca(OH)₂ = 74.093 g/mol
The number of moles of Ca(OH)₂ in the reaction, n₂ = 2.14 g/(74.093 g/mol) ≈ 0.029 moles
From the given chemical reaction, one mole of CaO reacts with one mole of H₂O to produce one mole of Ca(OH)₂
Therefore, 0.036 moles of CaO will produce 0.036 moles of Ca(OH)₂
Mass = Number of moles × Molar mass
The mass of 0.036 moles of Ca(OH)₂ ≈ 0.036 moles × 74.093 g/mol = 2.667348 grams
∴ The theoretical yield of Ca(OH)₂ = 2.667348 grams
[tex]Percentage \ yield = \dfrac{Actual \ yield}{Theoretical \ yield} \times 100 \%[/tex]
The percentage yield = (2.14 g)/(2.667348 grams) × 100 = 80.23%
Therefore, the option which is closest is option d. 81.1.
what oxide other than NO2 produce two acids when added to water?
Answer:
NO3 will produce 2 acids
how many significant figures are in 820 400.0 L
Answer:
7 significant numbers
How many gram of zinc will have to be treated with dilute hydrochloric acid to liberate 1.85 dm³ of hydrogen at 27°C and 750mmHg?
Answer:
Explanation:
given
volume=1.85 d m^3
T=27 degree C=27+273 k=300 k
P=750 mmHg
mass of zinc=?
we know that PV=nRT
n=m/M
PV=mRT/M
M for zinc=65.4
PVM=mRT
m=PVM/RT
m=750*1.85*65.4/0.0821*300
m=90742.5/24.63
m=3684
hope this will help u
Why is graphite slippery when pressed? Select one: a. covalent bonds break b. hexagonal layers slide c. molecules of graphite slide
Answer:
hexagonal layers slide
Explanation:
The layers in graphite can slide over each other because the forces between them are weak. The delocalised electrons are free to move through the structure, so graphite can conduct electricity.This makes graphite slippery, so it is useful as a lubricant .
i think it's right
hope it helps :)
What is atom economy? A. All of these B. The system that determines how much 1 mole of a pure element costs. C. The measure of how much of the reactants end up as products in a chemical reaction. D. The system of exchanging electrons that occurs in atoms.
Answer:
C
Explanation:
It's the amount of products you get compared to all the reactants you use. It's kind of like economy in that it's profit, and the higher the atom economy the more products/profit you have.
Answer:
C.) The measure of how much of the reactants end up as products in a chemical reaction.
Explanation:
I got it right on founders edtell.
How do experiments help scientists learn about the world?
A. Experiments explain scientific theories.
B. Experiments prove the scientists' hypotheses.
C. Experiments test the scientists' ideas.
D. Experiments correct old ideas.
Answer:
C. Experiments test the scientists' ideas.
Explanation:
Experiments test the scientists' ideas. Therefore, the correct option is C.
By testing ideas and hypotheses, experiments are an essential part of the scientific method and aid scientists' understanding of the world. Science uses regulated procedures to detect particular phenomena, track results, and collect data. These studies give researchers a chance to investigate cause-and-effect relationships, detect patterns, and draw conclusions based on the data. Scientists can test their ideas, theories, and predictions by systematically adjusting various factors to see whether experimental results confirm or disprove them.
Therefore, the correct option is C.
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Which of the following would be most likely to form a +2 cation?
The Periodic Table
A. Sulfur (S)
B. Calcium (Ca)
C. Chlorine (CI)
O D. Potassium (K)
Calcium because group 2 metals are all 2+ cations
How much energy has your body used, in joules, if your health
device indicates that 450 Calories were burned during your workout? How many
Calories are in a dinner containing 3.5 x 100 joules
Answer:
1,882.8 joules83.652 caloriesExplanation:
Given:
Amount in calories = 450 calories
Amount in joules = 3.5 × 100 joules
Find:
Change in joulesChange in caloriesComputation:
We know that,
1 calories = 4.184 joules
So,
Amount in calories = 450 calories
= 450 × 4.184
= 1,882.8 joules
Amount in joules = 3.5 × 100 joules
= [3.5 × 100] / 4.184
= 83.652 calories
16. I don't want to go anywhere apart from
Nairobi.
A. instead
B. only
C. besides
D. than
[tex]\huge\red{AnsweR:}[/tex]
I don't want to go anywhere apart from than Nairobi.
[tex]<font color=orange>[/tex]
A. instead
B. only
C. besides
D. than_______________________
#Be Brainly
You need 100.00 mL of H20 and 5.00 mL of
liquid plant food to make a solution for your
plants. You forgot to bring a measuring cup
out to the greenhouse, but you do have a scale
and know that the density of H2O is 1.00
g/cm", the density of liquid plant food is 1.21
g/cm' and 1 cm° = 1 mL. How much of the
liquid plant food would you use?
Answer:
6.05 g
Explanation:
Use the density to convert the volume to a weight.
(5.00 mL) × (1.21 g/mL) = 6.05 g liquid plant food
You will need 6.05 g liquid plant food.
Shalom, Guys!
The molar mass of strontium (\ce{Sr}SrS, r) is \pu{87.62 g/mol}87.62 g/mol87, point, 62, space, g, slash, m, o, l. Calculate the number of atoms in a \pu{67.5 mg}67.5 mg67, point, 5, space, m, g sample of \ce{Sr}SrS, r. Write your answer in scientific notation using three significant figures. \text{atoms Sr} ______________ atoms Sr
Love, Piper Rockelle
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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Identify each of the highlighted materials as an element, a compound, or a mixture, and explain your reasoning.
Answer:
These are compounds.
Explanation:
As it is formed by chemically bonding of two elements C ( carbon) and H (hydrogen) .
Its not a mixture because mixture is Just dispersed of diferrent elements or a compound which are not in fix ratioAnswer:
Butane and benzene are both compounds. They contain multiple elements bonded together in a specific ratio. Kerosene and gasoline are mixtures because they are combinations of several compounds. Oxygen is an element because it is made up of only one type of atom.
Explanation:
does the tendency to gain electrons decrease as we go down grp 17?
Explanation:
Hi, there!!!!
Let me simply clear you..
Yes,The tendency to gain electrons (in nonmetal) decreases when we go down group 17.
The reason for above answer is when we go downwards in periodic table then the atomic size increases with the addition of number of shells and force of attraction between the nucleus and valance shell decreases. The force of attraction between the nucleus and valance shell becomes weaker due to which the force of attracting the electrons gets decreased.
So, we can say that the tendency to gain electrons decreases as we go down in periodic table.
Hope it helps....
why hydrogen and oxygen all around us dows not form water
Answer:together doesn't make water
Explanation:
together doesn't make water
What is the concentration in moles per litre of:
a a sodium carbonate solution containing 53 g of the salt
(Na2CO3) in 1 litre?
b a copper(ll) sulfate solution containing 62.5 g of the salt
(CuSO4.5H20) in 1 litre?
Answer:
the concentration in moles per litre of is
Explanation:
Molarity
mark me as a a brainlist answer
Answer it answer it answer it
Answer:
[tex]\Large \boxed{\mathrm{A}}[/tex]
Explanation:
Rust formed from iron and oxygen combining is a chemical change, because in a chemical change, the resulting substance(s) will have different properties from the substance(s) before the chemical change.
I cant comment... So is it Right?
1. what is hard water.
2. Mention four sources of water.
3. write down the chemical formula of water.
4. What is purification of water.
5. Mention two importance of purification of water.
6. Mention 4 method used ot purify water. 7. Mention 4 impurities found in water.
8. Explain the term contaminated of water.
9. State two physical properties of water. 10. mention the names of of the elements that causes hardness in water.
Explanation:
Hard water is a type of water that can not easily lather with soap. Springs, wells, pipe-borneH20. The 2 is in basePurification of water is the cleansing of water to avoid diseases, germs, bacteria. To prevent diseases, to make the water safe for drinkingBoiling,chlorination, distillationSorry about number seven! This is when water is unsafe or dirty, it cannot be used for the purpose for which it is intended Water is tasteless, water is colourlessCalcium tetraoxosulphate(vi), Magnesium tetraoxo sulphate (vi) and Calcium hydrogen trioxocarbonate3.87 moles of iron bromide yielded10.4 moles of sodium bromide
Answer: 89.57 %
Hope it helps
URGENT PLS HELP What are derived units?
Answer:
A derived unit is a unit that results from a mathematical combination of SI base units. We have already discussed volume and energy as two examples of derived units.
Answer in the correct significant figures: 31.2 x 4.13*
Answer:
1.29* 10^2
Explanation:
multiply them and then round
begging u to answer Which is not an inter molecular force? Select one: a. Inter atomic bonds b. van der waals forces c. hydrogen bonds
Answer:
a-Interatomic bonds
Explanation:
First of all, it is not a force. Let alone be molecular force.
what is mean by stakeholder
Answer:
a stakeholder is a party that has an interest in a company and can either effect or be affected by the business. the primary stakeholder in a typical corporation are its investors , employees, customers and supplies.what is the molarity of a 50.0 ml aqueous solution containing 10.0 grams of acetic acid, ch3cooh?
Answer:
3.34 M or 3.34 mol/L
Explanation:
The formula for molarity is moles of solution ÷ liters of solution. So, we have to convert grams into moles and mL to L.
To convert grams to moles, first find the molar mass of CH₃COOH by looking at the atomic mass of each individual element.
C - 2(12.01) = 24.02
H - 4(1.01) = 4.04
O - 2(16.00) = 32.00
= 60.06
Now divide the number of grams by the molar mass.
10.0 g CH₃COOH ÷ 60.06 g = 0.167 mol CH₃COOH
To convert milliliters to liters, divide by 1000.
50.0 mL ÷ 1000 = 0.05 L
Now we can calculate the molarity.
M = moles of solution ÷ liters of solution
= 0.167 mol ÷ 0.05 L
= 3.34 M or 3.34 mol/L
The molarity is 3.34 M.
Hope that helps.