1) When hydrazine (N2H4) is burned in a 253-g brick container, the temperature of the brick increases by 5.13 degrees Celsius. Calculate the quantity of heat released in this raection. The specific heat of brick is 0.840 J/(gC).

2) A sample of coal is burned in a bomb calorimeter with a heat capacity of 4.62 KJ/C. The temperature in the calorimeter rises from 20.22 to 25.25 degrees celsius. Calculate the heat of the combustion reaction (qrxn) in KJ.

How do I solve these problems?

See your later post.

To solve these problems, you can use the formula for heat transfer: q = mcΔT, where q is the heat transferred, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature.

Let's solve the first problem:

1) First, we need to calculate the heat released when hydrazine is burned. We can use the formula q = mcΔT.

Given:
- Mass of the brick container (m) = 253 g
- Change in temperature (ΔT) = 5.13 °C
- Specific heat of the brick (c) = 0.840 J/(g°C)

Using the formula: q = mcΔT, we can substitute the values we have:

q = (253 g) x (0.840 J/(g°C)) x (5.13 °C)

Now, let's calculate the quantity of heat released:

q = 1096.848 J

Therefore, the quantity of heat released in this reaction is 1096.848 J.

Now, let's solve the second problem:

2) Similar to the first problem, we'll use the formula q = mcΔT.

Given:
- Change in temperature (ΔT) = 25.25 °C - 20.22 °C = 5.03 °C
- Heat capacity of the bomb calorimeter (c) = 4.62 kJ/°C

Note: The heat capacity is given in kilojoules, so we need to convert it to joules before using it in the formula.

c = 4.62 kJ/°C = 4620 J/°C

Using the formula: q = mcΔT, we can substitute the values we have:

q = (4620 J/°C) x (5.03 °C)

Now, let's calculate the heat of the combustion reaction:

q = 23214.6 J = 23.2 kJ

Therefore, the heat of the combustion reaction is 23.2 kJ.

Remember to always check your units and convert them if necessary.