Bleaching Powder

Q. iron oxide has formula Fe0.94O. what fraction of Fe exsist as Fe3+

Q.

The enthalpy of formation of NaCl can be calculated by using

1. 

2. 

3. 

4. 

Q.

Give the names of the elements present in the following compounds:

Baking powder

Q.

Passing carbon dioxide through slaked lime gives:

1. Ca(OH)₂

2. CaO

3. CaSO₄

4. CaCO₃

Q. 17. A 10 g mixture of Cu2S and CuS was treated with 200 ml of 0.75 M MnO4 in acid solution producing SO2, Cu22+ and Mn2+. The SO2 was boiled off and the excess MnO4 was titrated with 175 mL of 1 M Fe2+ solution. Calculate the percentage of CuS in the original solution Options: 42.6% 57.4% 27.6% 72.4%

Q. Q. 20.0 g of magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample? (At. wt. :Mg =24) (1) 60 (2) 84 (3) 75 (4) 96

Q. Calculate the percentage of available chlorine in a sample of $3.546g$ of bleaching powder which was dissolved in $100mL$ of water, $25mL$ of this solution, when treated with acetic acid and excess $KI$ , required $20mLof0.125N$ sodium thiosulphate solution.

1. $15.01\%$
2. $0.1\%$
3. $10.01\%$
4. $20.02\%$

Q. $Ca{\underset{–}{O}}_2$

Q. $1.25g$ of bleaching powder when treated with acetic acid and excess of $KI$, liberated iodine which required $37.5mL$ of $0.2N$ sodium thiosulphate solution. Calculate the percentage of available chlorine in the sample of bleaching powder.

1. $30.0\%$
2. $21.3\%$
3. $12.5\%$
4. $9.7\%$

Q. Auto-oxidation of bleaching powder yields:

1. $Ca(Cl{O}_3{)}_2$
2. $CaC{l}_2$
3. $Ca(OCl{)}_2$
4. Both a and b

Q. "Sodium silicate dissolved in water and its concentrated aqueous solution is called water glass."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Q. 20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample? (At. wt. Mg =24)

Q.

What is the oxidation state of chlorine in calcium salt of Bleaching Powder $Ca(OCl{)}_2$?

1. -1

2. -2

3. $+\frac{1}{2}$

4. +1

Q. Give reasons for the following observations: Addition of alum purifies water.

Q. Why is fluorine more electronegative than oxygen?

Q. The work is done in an open vessel when $113$ gm of $Fe$ reacts with dil. $HCl$ to form $FeC{l}_2$ at ${27}^o$C will be:

1. $w=-300$ cal
2. $w=-1200$ cal
3. $w=-600$ cal
4. $w=-200$ cal

Q. what is the formula for calculating oxidation state? and how to do those sums if asked?

Q. 20g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8g of magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample??

Q. Why enthalpy change is 0 for isothermal process?

Q.

Name two reagents which can be used to distinguish between ethene and

ethyne.

Q. Calculate the percentage of available chlorine in a sample of $3.546g$ of bleaching powder which was dissolved in $100mL$ of water, $25mL$ of this solution, when treated with acetic acid and excess $KI$ , required $20mLof0.125N$ sodium thiosulphate solution.

1. $15.01\%$
2. $0.1\%$
3. $10.01\%$
4. $20.02\%$

Q.

Write the formulae for the following compounds:

(a) Mercury(II) chloride (b) Nickel(II) sulphate

(c) Tin(IV) oxide (d) Thallium(I) sulphate

(e) Iron(III) sulphate (f) Chromium(III) oxide