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3 years ago

Calculate the number of moles in 4.22x1022 molecules of H,O

Chemistry

1 answer:

Arturiano [62]3 years ago

7 0

Answer:

0.07 moles of water

Explanation:

Given data:

Number of molecules of water = 4.22×10²²

Number of moles of water = ?

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules of water

4.22×10²² molecules × 1 mol /6.022 × 10²³ molecules

0.7 ×10⁻¹ mol

0.07 moles of water

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The number of mole of a molecule is defined as its mass per molar mass. Using # mol = n, mass = m and molar mass = M and given t

Citrus2011 [14]

Given:
n = 0.0021 mol
M = 44 gram/mol

Required: m or the mass of the molecule

Solution:

M = m/n

Rearranging the expression,

m = M x n
m = 44 g/mol x 0.0021 mol

Evaluating the expression and cancelling units, we obtain,

m = 0.0924 grams

M is the molar mass. This value is very useful in chemistry calculations especially in calculating the amounts of reactants and products for a chemical reaction.

5 0

3 years ago

How many molecules are in 3 moles of potassium bromide (KBr)

sattari [20]

Answer:

Your strategy here will be to use the molar mass of potassium bromide,

KBr

, as a conversion factor to help you find the mass of three moles of this compound.

So, a compound's molar mass essentially tells you the mass of one mole of said compound. Now, let's assume that you only have a periodic table to work with here.

Potassium bromide is an ionic compound that is made up of potassium cations,

, and bromide anions,

−

. Essentially, one formula unit of potassium bromide contains a potassium atom and a bromine atom.

Use the periodic table to find the molar masses of these two elements. You will find

For K:

39.0963 g mol

−

For Br:

79.904 g mol

−

To get the molar mass of one formula unit of potassium bromide, add the molar masses of the two elements

M KBr

39.0963 g mol

−

79.904 g mol

−

≈

119 g mol

−

So, if one mole of potassium bromide has a mas of

119 g

m it follows that three moles will have a mass of

moles KBr

⋅

molar mass of KBr



119 g

mole KBr

357 g

You should round this off to one sig fig, since that is how many sig figs you have for the number of moles of potassium bromide, but I'll leave it rounded to two sig figs

mass of 3 moles of KBr

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

360 g

∣

−−−−−−−−−

Explanation:

answer: 360 g 

6 0

3 years ago

How many moles are in 55.98g CF2Cl2

Karolina [17]

No of moles = given mass ÷ molecular mass
n = 55.98 ÷ (12+19×2+35.5×2)

7 0

3 years ago

Read 2 more answers

A sample of ice is heated continuously until it becomes a liquid, and then a gas. Its temperature is recorded throughout and a g

padilas [110]

Answer:

The answer to your question is: C. The specific latent heat of fusion

Explanation:

A. The specific latent heat of vaporization Specific latent heat of vaporization indicates the transition from liquid to vapor, but we are not looking for this definition. This answer is wrong.

B. The specific heat indicates the amount of heat needed to increase the temperature of water 1°C, so this answer is wrong.

C. The specific latent heat of fusion . This heat indicate the transition from solid ie to liquid, so this is the right answer.

D. The internal energy measures the energy of the molecules of a substance, so this answer is wrong.

3 0

3 years ago

What substance melts ice the fastest science project

arlik [135]

Answer:

Salt

Explanation:

salt particles make it harder for water particles to freeze back onto the ice

ice that is in contact with dissolved salt melts faster

7 0

2 years ago