Heat can be calculated using the formula:
U = mCpΔT
where:
U = internal energy or heat
m = mass of substance
Cp = specific heat capacity of a substance (constant)
ΔT = change in temperature = (Tf - Ti)
In the problem, we are given all these terms except for the Cp, which can help identify what the substance is. This is because Cp is unique and constant for a particular substance.
9760 = 200(Cp)(45-25)
Cp = 2.44 J/g-°C
Now, look for a library or list of specific heat capacities. Look for a substance that has the closest value to what you calculated. Based on data, the substance used is ethyl alcohol which has a Cp of exactly 2.44 J/g-°C
You can use this as reference: http://www.engineeringtoolbox.com/specific-heat-capacity-d_391.html
The law of conservation of mass States that mass in an isolation system is neither created nor destroyed by chemical reactions or physical transformations and the mass of the products in a chemical reaction must equal the mass of the reactants.
The frozen balloon shrank because the average kinetic energy of the gas molecules in a balloon decreases when the temperature decreases. This makes the molecules move more slowly and have less frequent and weaker collisions with the inside wall of the balloon, which causes the balloon to shrink a little.
The depletion of natural resources, the use of chemical and fuel in factories that increased air and water pollution , and increased the use of fossil fuels.
