Answer: 1.67 kg
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed=
=
(1kJ=1000J)
m= mass of substance = ?
c = specific heat capacity = 
Change in temperature ,
Putting in the values, we get:

(1kg=1000g)
Thus the mass (in kg) of the copper sample is 1.67
The SI unit for mass is Kilogram (kg).
Information would you need to know about the H₂O₂ solution is through stoichiometry experiment
The ideal gas constant R can be found experimentally by determining the number of moles of gas that occupies a particular measured volume at a known pressure and temprature and the H₂O₂ is a chemical compound used un various chemical reactions and is slightly viscous than water and the experiment by decomposition of hydrogen peroxide and using the ideal gas law rearrangement equation we can calculate the value of r and we will need the information such as concentration, volume and moles of H₂O₂ to determine its stoichiometry
Know more about ideal gas constant
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