From Kirchhoff's equation which factor affects the heat of reaction [MP PMT 1990]

1. Pressure

2. Temperature

3. Volume

4. Molecularity

The absolute enthalphy of neutralisation of the reaction $MgO\left(s\right)+2HCl\left(aq\right)\to MgC{l}_2\left(aq\right)+H_{2}O\left(l\right)$ will be [CBSE PMT 2005]

(1) Less than –57.33 kJ mol^–1

(2) –57.33 kJ mol^–1

(3) Greater than –57.33 kJ mol^–1

(4) 57.33 kJ mol^–1

The heat of transition (ΔH_t) of graphite into diamond would be, where

$C\left(\text{graphite}\right)+O_2\left(g\right)\to C{O}_2\left(g\right);\Delta H=xkJ$

$C\left(\text{diamond}\right)+O_2\left(g\right)\to C{O}_2\left(g\right);\Delta H=ykJ$ [Pb. PET 1985]

(1) $(x+y)kJmo{l}^{-1}$

(2) $(x-y)kJmo{l}^{-1}$

(3) $(y-x)kJmo{l}^{-1}$

(4) None of these

Given that
\(\small {2C(s) + 2O_2(g) \rightarrow 2CO_2(g); \Delta H = -787 kJ}\\ \small{ H_2(g) + {1 \over 2}O_2(g) \rightarrow H_2O(l) ; \Delta H = -286 kJ}\\ \small { C_2H_2(g) + 2 { 1 \over 2}O_2 (g) \rightarrow 2CO_2 (g) + H_2O (l) ; \Delta H= -1301 kJ}\)

The heat of the formation of acetylene is:
1. –1802 kJ

2. +1802 kJ

3. –800 kJ

4. +228 kJ

The enthalpy of combustion at 25°C of H₂, cyclohexane (C₆H₁₂) and cyclohexene (C₆H₁₀) are –241, –3920 and –3800 KJ / mole respectively. The heat of hydrogenation of cyclohexene is

(1) – 121 KJ / mole

(2) + 121 KJ / mole

(3) – 242 KJ / mole

(4) + 242 KJ / mole

The heat change for the reaction $H_{2 \left(g\right)} +\frac{1}{2}{O}_{2 \left(g\right)}\to H_{2}O$(l) is called

1. Heat of reaction

2. Heat of formation

3. Heat of vaporization

4. None of the above

The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^–1. The heat released when 0.5 mole of HNO₃ solution is mixed with 0.2 mole of KOH is [KCET 1991; AIIMS 2002; 

(1) 57.0 kJ

(2) 11.4 kJ

(3) 28.5 kJ

(4) 34.9 kJ

A solution of 500 ml of 0.2 M KOH and 500 ml of 0.2 M HCl is mixed and stirred; the rise in temperature is T₁. The experiment is repeated using 250 ml each of solution, the temperature raised is T₂. Which of the following is true

(1) T₁ = T₂

(2) T₁ = 2T₂

(3) T₁ = 4T₂

(4) T₂ = 9T₁

In the reaction for the transition of carbon in the diamond form to carbon in the graphite form, ΔH is –453.5 cal. This points out that

(1) Graphite is chemically different from diamond

(2) Graphite is as stable as diamond

(3) Graphite is more stable than diamond

(4) Diamond is more stable than graphite

Which of the following equations correctly represents the standard heat of formation $\left(\Delta H_f^o\right)$ of methane [IIT JEE (Screening) 1992]

(1) $C\left(diamond\right)+2H_2\left(g\right)=C{H}_4\left(g\right)$

(2) $C\left(graphite\right)+2H_2\left(g\right)=C{H}_4\left(l\right)$

(3) $C\left(graphite\right)+2H_2\left(g\right)=C{H}_4\left(g\right)$

(4) $C\left(graphite\right)+4H=C{H}_4\left(g\right)$