Question

At 19 ºC a volume of air takes us 9.0 mL in an expandable container. What is its volume after it is heated up to 50. ºC?

Answer 1

According to Charles law, we know, at constant pressure, volume is directly proportional to temperature. 
So, V/T = constant 

V₁/t₁ = V₂/t₂
V₁t₂ = V₂t₁

Here, we have: V₁ = 9 mL
V₂ = ?
T₂ = 50+272 = 323 K
T₁ = 19+273 = 292 K

Substitute their values into the expression:
9 × 323 = V₂ × 292
V₂ = 2907 / 292
V₂ = 9.95
After rounding-off to unit place value, it would be equal to 10 mL

So, In short Option C would be your correct answer.

Hope this helps!