whats the specific heat of an unknown substance if the addition of 800 joules of heat energy caused a 30 gram sample to warm from 20 to 40 degrees celsius?

The specific heat capacity of unknown substance is 1.333 g/j/°c

calculation

Specific heat capacity is calculated using Q = MCΔT formula

where;

Q (heat) = 800 j

M (mass) = 30 g

C (specific heat capacity) = ?

ΔT (change in temperature) = 40°c - 20°c = 20°c

make C the subject of the formula by diving both side of the formula by MΔT

C is therefore = Q/MΔT

800j / 30 g x 20°c = 1.333 j/g/°c