Question

1. How many moles are contained in 2.50 grams of benzoic acid? Molar mass of benzoic acid: 122.12 g/mol

2. How many mL are in 0.5 grams of cyclohexene? Density of cyclohexene is 0.809 g/ml

3. How many moles are in 250 mL of 2 M sodium hydroxide?

4. If 5.0 mL of 2-methyl-2-butanol are allowed to react with an excess of concentrated hydrochloric acid, what is the maximum mass of 2-chloro-2-methylbutane that can be obtained?

5. An acid-catalyzed dehydration of 10.0 grams of 2-methylpropan-2-ol produces 6.5 grams of 2-methylprop-1-ene. What is the percent yield for this reaction?

Please show correct sig figs

Answer 1

1)

Number of mol = mass / molar mass

= 2.50 g / 122.12 g/mol

= 0.0205 mol

Answer: 0.0205 mol

2)

Volume = mass / density

= 0.5 g / 0.809 g/mL

= 0.618 mL

Answer: 0.618 mL

3)

volume , V = 2.5*10^2 mL

= 0.25 L

use:

number of mol,

n = Molarity * Volume

= 2*0.25

= 0.5 mol

Answer: 0.5 mol

Only 1 question at a time please