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A 1.250 g sample of octane (C(8)H(18)) ...

A 1.250 g sample of octane `(C_(8)H_(18))` is burned in excess of oxygen in a bomb calorimeter. The temperatre of the calorimeter rises from 294.05 K to 300.78K. If heat capacity of the calorimeter is 8.93kJ`//`K, find the heat transferred to the calorimeter. Also calculate the enthalpy combustion of the sample of octane.

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To solve the problem, we will follow these steps: ### Step 1: Calculate the temperature change (ΔT) We need to find the change in temperature of the calorimeter. \[ \Delta T = T_{final} - T_{initial} \] Given: - \( T_{final} = 300.78 \, K \) - \( T_{initial} = 294.05 \, K \) Calculating ΔT: \[ \Delta T = 300.78 \, K - 294.05 \, K = 6.73 \, K \] ### Step 2: Calculate the heat transferred to the calorimeter (q) We use the formula: \[ q = C \cdot \Delta T \] Where: - \( C \) = heat capacity of the calorimeter = 8.93 kJ/K - \( \Delta T = 6.73 \, K \) Substituting the values: \[ q = 8.93 \, \text{kJ/K} \times 6.73 \, K = 60.00 \, \text{kJ} \] ### Step 3: Calculate the enthalpy of combustion per mole of octane First, we need to find the number of moles of octane burned. The molar mass of octane \( (C_8H_{18}) \) is calculated as follows: \[ \text{Molar mass of } C_8H_{18} = (8 \times 12.01) + (18 \times 1.008) = 114.22 \, g/mol \] Now, we find the number of moles in the 1.250 g sample: \[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{1.250 \, g}{114.22 \, g/mol} = 0.01095 \, mol \] Now, we can calculate the enthalpy of combustion per mole of octane: \[ \Delta H_{combustion} = \frac{q}{\text{number of moles}} = \frac{60.00 \, kJ}{0.01095 \, mol} = 5485.4 \, kJ/mol \] ### Final Results - Heat transferred to the calorimeter: **60.00 kJ** - Enthalpy of combustion of octane: **5485.4 kJ/mol** ---

To solve the problem, we will follow these steps: ### Step 1: Calculate the temperature change (ΔT) We need to find the change in temperature of the calorimeter. \[ \Delta T = T_{final} - T_{initial} \] ...
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A 1.250 g sample of octane (C_(8)H_(18)) is burned in excess of oxygen in a bomb calorimeter. The temperature of calorimeter rises from 294.05 K to 300.78 K . If heat capacity of the calorimeter is 8.93 kJ K^(-1) , find the heat transferred to calorimeter.

A 1.25g sample of octane (C_(8)H_(18)) is burnt in excess of oxygen in a bomb calorimeter. The temperature of the calorimeter rises from 294.05 to 300.78 K. If heat capacity of the calorimeter is 8.93 kJ K^(-1) . Find the heat transferred to calorimeter.

Knowledge Check

  • In a calorimeter, the temperature of the calorimeter increases by 6.12 K, the heat capacity of the systemm is 1.23 kJ/g/deg. What is the molar heat of decomposition for the ammonium nitrate?

    A
    `-7.53kJ//mol`
    B
    `-398.1kJ//mol`
    C
    `-16.1kJ//mol`
    D
    `-602kJ//mol`
  • One gram sample of NH_(4)NO_(3) is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.23K . The heat capacity of the system is 1.23kJ //g-deg . The molar heat of decomposition for NH_(4)NO_(3) is :

    A
    `-16.1kJ mol^(-1)`
    B
    `-7.53kJ mol^(-1)`
    C
    `-621.89kJ mol^(-1)`
    D
    `-498.1kJ mol^(-1)`
  • One gram sample of NH_(4)NO_(3) is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K the heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for NH_(4)NO_(3)

    A
    `-7.53` kJ/mol
    B
    `-398.1 kJ//mol`
    C
    `-16.1` kJ/mol
    D
    `-602` kJ/mol
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