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2 years ago

How many molecules are in 3.5 moles of hydrogen

Chemistry

1 answer:

jek_recluse [69]2 years ago

7 0

Answer:3.5 moles * 6.02 X 10^23 particles/mole * 2 H atoms/particle of H2 = 42.14 X 10^^23 atoms

Explanation:

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The coiling of the protein chain backbone into an alpha helix (like a spring) is referred to as the ________.

Agata [3.3K]

Answer: secondary structure

Explanation:

5 0

4 years ago

What is the molarity of SO4^2- in a solution prepared by mixing 2.17 g of alum, KAl(SO4)2•12H2O, with 175 mL of water? The molec

vodka [1.7K]

<u>Answer:</u> The concentration of sulfate ions in the solution is 0.0522 M

<u>Explanation:</u>

To calculate the the molarity of solution:, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

Given mass of alum = 2.17 g

Molar mass of alum = 478.39 g/mol

Volume of solution = 175 mL

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{2.17\times 1000}{474.39\times 175}\\\\\text{Molarity of solution}=0.0261M$

The chemical equation for the ionization of alum follows:

$KAl(SO_4)_2.12H_2O\rightarrow K^++Al^{3+}+2SO_4^{2-}+12H_2O$

1 mole of alum produces 1 mole of potassium ions, 1 mole of aluminium ions, 2 moles of sulfate ions and 12 moles of water

So, concentration of sulfate ions = $(2\times 0.0261)=0.0522M$

Hence, the concentration of sulfate ions in the solution is 0.0522 M

4 0

3 years ago

A student wants to prepare exactly 250 ml of a 0.500 m aqueous potassium hydroxide solution. what mass of potassium hydroxide (m

uranmaximum [27]

Molarity is defined as the number of moles of solute in volume of 1 L solution.
the molarity of KOH solution to be prepared is 0.500 M
the volume of solution to be prepared is 250 mL
the number of KOH moles in 1 L - 0.500 mol
therefore number of KOH moles in 250 mL - 0.500 mol/L x 0.250 L = 0.125 mol
Mass of KOH in 0.125 mol - 0.125 mol x 56.10 g/mol = 7.01 g
The mass of KOH required to make the solution is therefore 7.01 g

7 0

3 years ago

What do you need in order to do a stoichiometric calculation? (Choose

expeople1 [14]

I think it is Molar masses of compounds involved or Oxidation numbers, but you can choose one of them. Or you can think about the question carefully.

3 0

3 years ago

Express 7.25 in scientific notation

shutvik [7]

7.25 x 10 , Hope this helps out.

5 0

3 years ago

Read 2 more answers