Question

When 40.0 mL of 1.00 M H2SO4 is added to 80.0 mL of 1.00 M NaOH at 20.00°C in a coffee cup calorimeter, the temperature of the aqueous solution increases to 29.20°C. If the mass of the solution is 120.0 g and the specific heat of the calorimeter and solution is 4.184 J/g • °C, how much heat is given off in the reaction? (Ignore the mass of the calorimeter in the calculation.) Use q=mCp(tiangle)t

4.62 kJ
10.0 kJ
14.7 kJ
38.5 kJ

Answer 1

A. 4.62kJ

Step-by-step explanation:

Answer 2

`\boxed{\text{4.62 kJ}}`

Step-by-step explanation:

There are two heat transfers to consider:

`\begin{array}{ccccc}\text{Heat released by reaction} & + &\text{heat absorbed by water} & =& 0\\q_(1)& + & q_(2) & = & 0\\q_(1)& + & mC_(p)\Delta T & = & 0\\\end{array}`

Calculate q₂

m = 120.0 g

C = 4.184 J·°C⁻¹g⁻¹

T₂ = 29.20 °C

T₁ = 20.00 °C

ΔT = T₂ - T₁ =(29.20 – 20.00) °C =9.20 °C

q₂ = 120.0 g × 4.184 J·°C⁻¹g⁻¹ × 9.20 °C = 4620 J = 4.62 kJ

Calculate q₁

q₁ + 4.62 kJ = 0

q₁ = -4.62 kJ

The negative sign shows that heat is given off.

`\text{The reaction gives off }\boxed{\textbf{4.62 kJ}}`