2023
JEE Mains
Numerical
JEE Main 2023 (Online) 11th April Evening Shift
$\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2} \cdot \mathrm{XH}_{2} \mathrm{O}$ and $\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2} \cdot \mathrm{YH}_{2} \mathrm{O}$, represent formula of the crystalline forms of nitrate salts. Sum of $\mathrm{X}$ and $\mathrm{Y}$ is _____________.
Correct Answer: 6
Explanation:
Magnesium nitrate typically crystallizes as a hexahydrate, which means it has six water molecules in its crystal structure. So, X = 6.
On the other hand, barium nitrate commonly crystallizes as an anhydrous salt, meaning it does not incorporate water molecules into its crystal structure. So, Y = 0.
Therefore, the sum of X and Y would indeed be 6 + 0 = 6.
2023
JEE Mains
Numerical
JEE Main 2023 (Online) 31st January Evening Shift
The number of alkali metal(s), from $\mathrm{Li}, \mathrm{K}, \mathrm{Cs}$, Rb having ionization enthalpy greater than $400 \mathrm{~kJ}$ $\mathrm{mol}^{-1}$ and forming stable super oxide is _____________.
Correct Answer: 2
Explanation:
Li does not form superoxide.
K, Rb and Cs form stable super oxides but Cs has ionisation enthalpy less than 400 kJ. While K and Rb have ionisation enthalpy greater than 400 kJ mol–1.
2023
JEE Mains
Numerical
JEE Main 2023 (Online) 29th January Evening Shift
On heating, $\mathrm{LiNO_3}$ gives how many compounds among the following __________
$\mathrm{Li_2O,N_2,O_2,LiNO_2,NO_2}$
Correct Answer: 3
Explanation:
$\mathrm{LiNO_3\buildrel \Delta \over \longrightarrow Li_2O+NO_2+O_2}$
2022
JEE Mains
Numerical
JEE Main 2022 (Online) 27th June Evening Shift
BeO reacts with HF in presence of ammonia to give [A] which on thermal decomposition produces [B] and ammonium fluoride. Oxidation state of Be in [A] is ____________.
Correct Answer: 2
Explanation:
$
\mathrm{BeO}+2 \mathrm{NH}_3+4 \mathrm{HF} \longrightarrow\underset{\text { (A) }}{\left(\mathrm{NH}_4\right)_2\left[\mathrm{BeF}_4\right]}
$
$ \left(\mathrm{NH}_4\right)_2\left(\mathrm{BeF}_4\right) \stackrel{\text { Heating }}{\longrightarrow} \underset{\text { (B) }}{\mathrm{BeF}_2}+2 \mathrm{NH}_4 \mathrm{~F} $
Oxidation State of Be in $(A)$ is $(+2)$
$ \left(\mathrm{NH}_4\right)_2\left(\mathrm{BeF}_4\right) \stackrel{\text { Heating }}{\longrightarrow} \underset{\text { (B) }}{\mathrm{BeF}_2}+2 \mathrm{NH}_4 \mathrm{~F} $
Oxidation State of Be in $(A)$ is $(+2)$
2011
JEE Advanced
Numerical
IIT-JEE 2011 Paper 1 Offline
Reaction of Br2 with Na2CO3 in aqueous solution gives sodium bromide and sodium bromate with evolution of CO2 gas. The number of sodium bromide molecules involved in the balanced chemical equation is ________.
Correct Answer: 5
Explanation:
The balanced chemical equation is
3Na2CO3 + 3Br2 $\to$ 5NaBr + NaBrO3 + 3CO2
1999
JEE Advanced
Numerical
IIT-JEE 1999
Give reasons of the following:
BeCl2 can be easily hydrolysed.
BeCl2 can be easily hydrolysed.
Correct Answer: Solve by yourself
1998
JEE Advanced
Numerical
IIT-JEE 1998
Work out the following using chemical equation :
Chlorination of calcium hydroxide produces bleaching powder.
Chlorination of calcium hydroxide produces bleaching powder.
Correct Answer: Solve by yourself
1997
JEE Advanced
Numerical
IIT-JEE 1997
Element A burns in nitrogen to give an ionic compound B. Compound B reacts with water to give C and D. A solution of C becomes 'milky' on bubbling carbon dioxide. Identify A, B, C and D.
Correct Answer: Ba, Ba<sub>3</sub>NO<sub>2</sub>, Ba(OH)<sub>2</sub>, BaCO<sub>3</sub>
1997
JEE Advanced
Numerical
IIT-JEE 1997
Arrange the following sulphates of Alkaline earth metals in order of decreasing thermal stability : BeSO4, MgSO4, CaSO4, SrSO4
Correct Answer: SrSO<sub>4</sub> > CaSO<sub>4</sub> > MgSO<sub>4</sub> > BeSO<sub>4</sub>
1997
JEE Advanced
Numerical
IIT-JEE 1997
Give reasons of the following:
The crystalline salts of alkaline earth metals contain more water of crystallisation than the corresponding alkali metal salts.
The crystalline salts of alkaline earth metals contain more water of crystallisation than the corresponding alkali metal salts.
Correct Answer: Solve by your self
1996
JEE Advanced
Numerical
IIT-JEE 1996
Explain the difference in the nature of bonding in LiF and LiI.
Correct Answer: Solve by yourself
1994
JEE Advanced
Numerical
IIT-JEE 1994
Complete and balance the following reactions:
Ca5(PO4)3F + H2SO4 + H2O $\buildrel {Heat} \over \longrightarrow $ ........ + 5CaSO4.2H2O + ........
Ca5(PO4)3F + H2SO4 + H2O $\buildrel {Heat} \over \longrightarrow $ ........ + 5CaSO4.2H2O + ........
Correct Answer: Ca<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F + 5H<sub>2</sub>SO<sub>4</sub> + 10H<sub>2</sub>O $$\buildrel {Heat} \over
\longrightarrow $$ 3H<sub>3</sub>PO<sub>4</sub> + 5CaSO<sub>4</sub>.2H<sub>2</sub>O + HF
1991
JEE Advanced
Numerical
IIT-JEE 1991
Write down the balanced equation for the reaction when:
Carbon dioxide is passed through a suspension of lime stone in water.
Carbon dioxide is passed through a suspension of lime stone in water.
Correct Answer: Solve by yourself.
1989
JEE Advanced
Numerical
IIT-JEE 1989
Write down the balanced equation for the reaction when:
Potassium ferricyanide reacts with hydrogen peroxide in basic solution
Potassium ferricyanide reacts with hydrogen peroxide in basic solution
Correct Answer: Solve by yourself
1988
JEE Advanced
Numerical
IIT-JEE 1988
Write down the balanced equation for the reaction when:
Carbon dioxide is passed through a concentrated aqueous solution of sodium chloride saturated with ammonia.
Carbon dioxide is passed through a concentrated aqueous solution of sodium chloride saturated with ammonia.
Correct Answer: Solve by yourself
1987
JEE Advanced
Numerical
IIT-JEE 1987
Give reasons of the following :
Magnesium oxide is used for the lining of steel making furnace.
Magnesium oxide is used for the lining of steel making furnace.
Correct Answer: Do by yourself
1985
JEE Advanced
Numerical
IIT-JEE 1985
Write down the balanced equations for the reaction when:
Calcium phosphate is heated with a mixture of sand and carbon;
Calcium phosphate is heated with a mixture of sand and carbon;
Correct Answer: Solve by yourself
1982
JEE Advanced
Numerical
IIT-JEE 1982
How will you prepare bleaching powder from slaked lime.
Correct Answer: Solve by yourself
1982
JEE Advanced
Numerical
IIT-JEE 1982
Write down the balanced equations for the reaction when:
An alkaline solution of potassium ferricyanide is reacted with hydrogen peroxide.
An alkaline solution of potassium ferricyanide is reacted with hydrogen peroxide.
Correct Answer: Solve by yourself
1981
JEE Advanced
Numerical
IIT-JEE 1981
Give reasons of the following:
Sodium carbonate is made by Solvay process but the same process is not extended to the manufacture of potassium carbonate.
Sodium carbonate is made by Solvay process but the same process is not extended to the manufacture of potassium carbonate.
Correct Answer: Do by yourself
1993
JEE Advanced
Numerical
IIT-JEE 1993
Ca2+ has a small ionic radius than K+ because it has ______.
Correct Answer: higher effective nuclear charge
1989
JEE Advanced
Numerical
IIT-JEE 1989
The electrolysis of molten sodium hydride liberates ____ gas at the _____
Correct Answer: hydrogen, anode
1985
JEE Advanced
Numerical
IIT-JEE 1985
Sodium dissolved in liquid ammonia conducts electricity because ________.
Correct Answer: of solvated electrons
1980
JEE Advanced
Numerical
IIT-JEE 1980
Anhydrous MgCl2 is obtained by hydrated salt with ______.
Correct Answer: Anhydrous HCl