Question

It requires 350 joules to raise a certain amount of a
substance from 10.0°C to 30.0°C. The specific heat of
the substance is 1.2 J/g°C.

Q. What is the mass of the substance?

12g
15g
18g
30g

Answer 1

Answer:

Mass of matter:

m = 15 g

Explanation:

Given:

Q =350 J

t₁ = 10.0°C

t₂ = 30.0°C

c = 1,2 J / (g·°C)

______________

Q -?

Required energy:

Q =c·m·(t₂ - t₁)

Mass of matter:

m = Q / (c·(t₂ - t₁))

m= 350 / (1.2·(30.0 - 10.0)) = 350 / 24 ≈ 15 g

Answer 2

Answer:

15 g

Explanation:

Specific Heat Capacity

$\large\boxed{\Delta E_t=m \times c \times \Delta \theta}$

Where:

• $\Delta E_t$ = Change in thermal energy measured in joules (J).
• m = Mass measured in kilograms (kg).
• c = Specific heat capacity measured in joules per kilogram per degree Celsius (J/kg°C)
• $\Delta \theta$ = Temperature change measured in degrees Celsius (°C).

Given:

• $\Delta E_t = 350\; \sf J$
• $c = 1.2\; \sf J/g^{\circ}C$
• $\Delta \theta = 30^{\circ} \sf C-10^{\circ} C=20^{\circ} C$

As the specific heat capacity is given in J/g°C, the temperature is given in °C, and the mass is in grams, no conversion of units is necessary.

Substitute the values into the formula and solve for m:

$\begin{aligned}\Delta E_t & =m \times c \times \Delta \theta\\\implies 350 & = m \times 1.2 \times 20\\350 & = 24m\\m & = \dfrac{350}{24}\\m & =14.58333...\; \sf g\end{aligned}$

Therefore, the mass of the substance is 15 g (nearest whole number).