When a 1.06 g sample of Compound Q, a nonelectrolyte, is dissolved in 11.6 g of water, the boiling point of the resulting solution is 100.47 ˚C. The boiling point of pure water is 100.00 ˚C, and the Kb for water is 0.512 ˚C/m. Determine the molar mass of Compound Q.

The molar mass of compound Q is 100 g/mol

Explanation:

Step 1: Data given

Mass of compound Q = 1.06 grams

Mass of water = 11.6 grams

Boiling point of the solution = 100.47 °C

Boiling point of water = 100.00 °C

Kb for water = 0.512 °C/m

Step 2: Calculate molality

ΔT = i*kb*m

⇒ with ΔT = the boiling point elevation = 0.47 °C

⇒ with i = the van't Hoff factor = 1

⇒ with kb = the boiling point elevation constant = 0.512 °C/m

⇒ with m = the molality = moles compound Q / mass water

m = ΔT / (i*Kb)

m = 0.47 / 0.512

m = 0.918 molal

Step 3: Calculate moles of Q

Molality = moles Q / mass H2O

moles Q = 0.918 molal * 0.0116 kg

moles Q = 0.0106 moles

Step 4: Calculate molar mass

Molar mass Q = mass Q / moles Q

Molar mass Q = 1.06 grams / 0.0106 moles

Molar mass Q = 100 g/mol

The molar mass of compound Q is 100 g/mol

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).