1. One-use heating pads generate heat when a salt such as calcium chloride is di

Question

1. One-use heating pads generate heat when a salt such as calcium chloride is dissolved in water. Which of the following statements is true about the process that occurs in these heating pads?

a. q > 0; process is endothermic

b. q < 0; process is endothermic

c. q > 0; process is exothermic

d. q < 0; process is exothermic

2. The heat capacity of an object is defined as:
a. the energy required to raise the temperature of 1 gram of a substance by 1 °C.
b. the energy required to raise the temperature of 1 mole of a substance by 1 °C.
c. the energy required to raise the temperature of an object by 1 °C.
d. the energy required to raise the temperature of an object from its melting point to its boiling point.

3. Natural gas, or methane, is an important fuel. Combustion of one mole of methane releases 802.3 kilojoules of energy. How much energy does that represent in kilocalories?

a. 3.36 kcal
b. 192 kcal
c. 3360 kcal
d. 192000 kcal

Explanation / Answer

Ans 1:d) q<0 ; process is exothermic

Since these are heating pads , which release heat which means that the reaction is exothermic. This means that the heat is released in the products side which is more than that the heat absorbed in the reactant side.

So the q is negative , i.e. <0

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