Chemistry questions HELP please?

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Namtrix

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1. Whats' the atomic mass in grams of 0.35 moles of CH4?
2. How many grams of CO are in 125 ml of a 0.25 molal solution
3. Calculate the number of molecules in 0.75 moles of CH4
4. Potassium fluoride (KF), a salt, has a molecular weight of 58.10 grams. How many grams would be needed to make 1.0 liter of 5.0 molar salt solution
5. Potassium fluoride (KF), a salt, has a molecular weight of 58.10 grams. How many grams would be needed to mix 1.0 liter of 0.10 M salt solution?
 
1. mass of C=12g/mol, mass of H=1g/mol
==> mass of CH4=16g/mol, (16g/mol)*0.35mol= 5.6g

2. 0.25mol/1000ml*(12g/mol+16g/mol)*125ml= 0.875g
(I used .25 molar vice .25 molal, because you need to grams
of solvent to use Molality)

3. 6.02*10^23 molecules/mole * 0.75 Moles = 4.515*10^23 molecules

4. 5.0 Mol/L * 1.0L * 58.10 g/mol = 290.5g

5. .10 Mol/L * 1.0L * 58.10 g/mol = 5.81g
 
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