Question

A substance of unknown mass absorbs 1932 joules of energy, going from 26 to 42 degrees Celsius. If the specific heat of the substance is 4.29 J/g·°C, how much of the substance is present?

2.8 g
6.6 g
66.2 g
28 g

Answer 1

Answer : The mass of the substance is, 28 g

Solution :

Formula used :

`Q=m* c* \Delta T=m* c* (T_(final)-T_(initial))`

where,

Q = heat absorbs = 1932 J

m = mass of the substance = ?

c = specific heat of substance =
`4.29J/g^oC`

`\Delta T=\text{Change in temperature}`

`T_(final)` = final temperature =
`42^oC`

`T_(initial)` = initial temperature =
`26^oC`

Now put all the given values in the above formula, we get the mass of the substance.

`1932J=m* 4.29J/g^oC* (42-26)^oC`

`m=28.146g=28g`

Therefore, the mass of the substance is, 28 g