Uses of alkali and alkaline earth metals - class-XI
uses of alkali and alkaline earth metals
Questions
$MCrO _{4(s)}\overset{CH _{3}COOH(aq)}{\rightarrow}MCrO _{4}$ ( Suspension) above change is correct for which metal ion (s) ?
- $Ba^{2+},Sr^{2+},Ca^{2+}$
- $Ba^{2+},Sr^{2+}$
- Only $Ba^{2+}$
- $Sr^{2+},Ca^{2+}$
Which is the major constituent of gun powder?
- Nitre
- Sulphur
- Charocal
- Chile salt petre
The common name, "cream of tartar" refers to :
- $KHC _{4}H _{4}O _{6}$
- $K(SbO)C _{4}H _{4}O _{6}$
- $KNaC _{4}H _{4}O _{6}$
- $Mg _{2} (OH) _{2}(C _{4}H _{4}O _{6})H _{2}O$
$Sr^{2+}$ forms a very unstable complex with $NO _{3-}$. A solution that was $0.001 M - Sr(ClO _{4}) _{2}$ and $0.05 M - KNO _{3}$ was found to have only $75$% of its strontium in the uncomplexed $Sr^{2+}$ form, the balance being $Sr(NO _{3})^{+}$. What is $K _{f}$ for complexation?
- $6.67$
- $0.15$
- $60$
- $26.67$
Potash alum is represented by the formula :
- $K _2SO _4\cdot Al _2(SO _4) _3\cdot 24H _2O$
- $K\cdot Al(SO _4) _2\cdot 12 H _2O$
- Both (a) and (b)
- None of these
$KO _2$ (potassium superoxide) is used in oxygen cylinders in space and submarines because, it :
- decomposes to give oxygen
- eliminates moisture
- absorbs $CO _2$
- produces ozone
In the reaction : $K _4[Fe(CN) _6] + K _2CO _3\rightarrow $ the product formed is :
- $FeCO _3$
- $KCN$
- $KFeCO _3$
- $K _3 [Fe(CN) _6]$
${K} _{2}C{S} _{3}$ can be called potassium :
- Sulphocyanide
- Thiocarbide
- Thiocarbonate
- Thiocyanate
The material used in photoelectric cells contains:
- $Cs$
- $Si$
- $Sn$
- $Ti$
Metallic sodium is used as a drying agent for :
- chloroform
- cyclohexane
- diispropyl ether
- diethylamine
Read the assertion and reason carefully and answer the question on the basis of the following options. You have to select the one that best describes the two statements.
Reason: Potassium and caesium emit electrons on exposure to light.
- If both assertion and reason are true and the reason is a correct explanation of the assertion
- If both assertion and reason are true but reason is not a correct explanation of the assertion
- If the assertion is true but reason is false
- If both the assertion and reason are false
- If the assertion is false but the reason is true
At night when the lights of a scooter or a car fall on a road-sign or on a vehicle moving ahead, the painted letters or numbers shine with a glow. Which of the following is a luminous paint?
- Nickel-chrome alloy
- Barium sulphide
- Silver-plated metal
- None of these
A metal salt solution forms a yellow precipitate with potassium chromate in acetic acid, a white precipitate with dilute sulphuric acid but does not give precipitate with sodium chloride or iodide. The white precipitate obtained when sodium carbonate is added to the metal salt solution will consist of:
- lead carbonate
- basic lead carbonate
- barium carbonate
- strontium carbonate
Beautiful colours of fireworks are produced by adding salts of various metals into the burning mixture. The firework colours of different metals are mentioned here. Pick the false one.
- Calcium gives a brick-red light
- Sodium gives a yellow light
- Copper gives a green light
- Strontium gives a blue light
Sparkling red colour after the blast of fire crackers is due to the presence of:
- sulphur
- sodium
- strontium
- magnesium