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3 years ago

How many particles are present in one mole of particles?

Chemistry

1 answer:

astraxan [27]3 years ago

3 0

D) 6.02 × 10^23

This number is called Avogadro's number and represents the number of moles in 12 grams of Carbon-12.

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Which term describes matter that is a substance made of diffrent kinds of atoms bonded together

Alex777 [14]

Compounds are substances made of at least 2 different elements. Molecules have at least 2 atoms, doesn't have to be different elements. Compounds and molecules both work.

8 0

3 years ago

If evaporation occurs what will change 0.70 molar solution of CuSO4

faust18 [17]

Answer:

A. Molarity will increase .

Explanation:

Molarity = moles of solute per litre of solution

= moles of solute / volume of solution

If evaporation occurs , volume of solution decreases and moles of solute remains constant . Hence denominator decreases and numerator remains constant .

Hence the molarity increases .

3 0

3 years ago

Which of these are true for a hypothesis? (You can pick more than one)

Naya [18.7K]

Hypotheisis is just like an initial building block for a building. The true statements about hypothesis among the given are-

First guess- hypothesis is a proposed explanation for something which is observed. Thus the explanation is just a guess and not a proved one.
An initial idea which is assumed to be true - The whole experiment or research is based on an assumption which is supposed to be true and the scientist works to prove that true.

6 0

3 years ago

Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

Paha777 [63]

Answer:

There is 9671 Kj of heat released

Explanation:

Step 1: The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

Step 2: Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

Step 3: Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

Step 4: Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will completely react

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

Step 5: Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671 Kj of heat released

6 0

3 years ago

Lets say you were doing an experiment on two different chemicals in two different test tubes. One chemical is giving off oxygen

boyakko [2]

Answer:

Tests for gases

Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.

Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.

Oxygen. A glowing wooden splint relights in a test tube of oxygen.

hope it will help

5 0

3 years ago