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If a system is expanded under adiabatic process, then:
Which pair of the following compounds has one lone pair of electrons on the central atom?
Joule-Thomson expansion is [JIPMER 2000]:
If the head of cockroach is removed, it may live for few days because
In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be:
The values of $\Delta H$ and $\Delta S$ for the given reaction are $170 \text{ kJ}$ and $170 \text{ J K}^{-1}$, respectively. $C(\text{graphite}) + CO_2(g) \rightarrow 2CO(g)$ This reaction will be spontaneous at:
The heat of neutralisation of a strong acid and a strong alkali is $57.0 \text{ kJ mol}^{-1}$. The heat released when $0.5 \text{ mole of } HNO_{3}$ solution is mixed with $0.2 \text{ mole of } KOH$ is [KCET 1991; AIIMS 2002]:
What is the value of $K_{sp}$ of $\text{Ag}_2\text{CO}_3\text{(s)}$ in water at $25^\circ\text{C}$ for the following reaction: $\text{Ag}_2\text{CO}_3\text{(s)} \rightarrow 2\text{Ag}^+\text{(aq)} + \text{CO}_3^{2-}\text{(aq)}$? [Given: $R=8.314 \text{ J K}^{–1}\text{ mol}^{–1}$; $\Delta G^\circ=+63.3 \text{ kJ}$]
A resistance wire connected in the left gap of a metre bridge balances a $10 \ \Omega$ resistance in the right gap at a point which divides the bridge wire in the ratio $3 : 2$. If the length of the resistance wire is $1.5 \text{ m}$, then the length of $1 \ \Omega$ of the resistance wire is :
The boiling point of 0.2 mol kg⁻¹ solution of X in water is greater than the equimolal solution of Y in water. The correct statement in this case is:
Equal volumes of monoatomic and diatomic gases at the same initial temperature and pressure are mixed. The ratio of specific heats of the mixture ($C_p/C_v$) will be [AFMC 2002]:
The standard enthalpy and standard entropy changes for the oxidation of ammonia at $298\text{ K}$ are $-382.64\text{ kJ mol}^{-1}$ and $-145.6\text{ J K}^{-1}\text{ mol}^{-1}$, respectively. Standard Gibbs energy change for the same reaction at $298\text{ K}$ is:
In which of the following processes entropy increases? A. A liquid evaporates to vapour. B. Temperature of a crystalline solid lowered from 130 K to 0 K. C. 2NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g) D. Cl2(g) → 2Cl(g) Choose the correct answer from the options given below:
Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are :
In water hyacinth and water lily, pollination takes place by :
Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water? The heats of solution ($\Delta H_{sol}$) of these compounds at $25^{\circ}C$ in kJ/mol of each solute are given in brackets [AMU (Engg.) 2000]:
A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy $\Delta U$ of the gas in joules will be:
Enthalpy of combustion of carbon to carbon dioxide is −390.0 kJ mol⁻¹. The amount of heat released when 35.0 g of CO2 is formed from the reaction of carbon and dioxygen gas, is:
Heat of combustion $\Delta H^\circ$ for $C(s)$, $H_2(g)$ and $CH_4(g)$ are $-94$, $-68$ and $-213\text{ Kcal/mol}$. $\Delta H^\circ$ for $C(s) + 2H_2(g) \rightarrow CH_4 (g)$ is:
Select the correct statement/s with respect to mechanism of sex determination in Grasshopper. A: It is an example of female heterogamety B: Male produces two different types of gametes either with or without X chromosomes. C: Total number of chromosomes (autosomes and sex chromosomes) is same in both males and females. D: All eggs bear an additional X chromosome besides the autosomes. Choose the correct answer from the options given below: