Physical Properties

Q. Sodium Carbonate reacts with dilute sulphuric acid to give the respective salt, water and carbon dioxide.Calculate the mass of the pure salt formed when 300g of sodium carbonte of 80% purity reacts with dilute sulphuric acid.

Q. If the density of Lake water is 1.25g/ml and contains 92 g of sodium ions per kg of water, calculate molarity in the Lake.

Q.

Give a reason for the higher boiling point of ethanol in comparison to methoxymethane.

Q.

Acid employed for etching of glass is?

1. $\mathrm{HCl}$

2. ${\mathrm{HNO}}_3$

3. Aqua-regia

4. $\mathrm{HF}$

Q.

An organic compound has the following percentage composition: C = 12.76%, H = 2.13%, Br = 85.11%. The vapour density of the compound is 94. Find out its molecular formula [C = 12, H = 1, Br = 80].

Q.

The density of sulphuric acid is ___ the density of water.

1. less than or equal to

2. less than

3. greater than

4. equal to

Q. Density of lithium atom is 0.53gcm-3.The edge length of Li is 3.5 .Find out the no of Li atoms in an unit cell.(M=6 94gmol-1)

Q.

Butyric acid contains only C, H, O. A 4.24mg sample of butyric acid is completely burnt. It gives 8.45mg of CO2 and 3.46mg of H2O. What is the mass percentage of each element in butyric acid? The molecular mass of butyric acid was determined by experiment to be 88 a.m.u. What is the molecular formula?

Please help me solve this question briefly!!!

Q.

What is the colour of Nitric Acid?

1. colourless

2. Pure Nitric Acid (conc) is colourless and commercial Nitric Acid is yellowish brown.

3. Yellowish Brown

4. None of the above

Q.

Na2CO3+Hcl, _______≥NaCL+NaHCO3. Na2CO3+HcL________≥NaCL+H2o+CO2 why is it written like that , is this equation both write?

Q.

Two organic compounds X and Y contain Carbon and Hydrogen only and have vapour densities 13 and 39 respectively. State the molecular formula of X and Y.

Q. 0.45 g of an organic compound gave 0.44g of CO2 and 0.09g of H2O. The molecular mass of the compound is 90amu. Calculate the molecular formula.

Q. Why is the boiling point of sulphuric acid very high?

1. Force of attraction due to polarity
2. High molecular mass
3. Low molecular mass
4. Both A and B

Q.

Carbon compounds have usually .......... melting points and boiling points because they are .......... in nature.

Q.

Why can't sulphur form as many bonds , allotrpes as carbon , although both of them have the same valency of 4?,

Q. While constructing a house a builder selects marble flooring and marble top for kitchen where vinegar and uses of lemon, tamarind are more often used for cooking. will you agree to this selection and why

Q. Nitric acid cannot be concentrated beyond 68% by the distillation of a dilute solution of $HN{O}_3$. State the reason. [2 MARKS]

Q.

Sulfur is a solid at room temperature, while sulfur dioxide is a gas. Explain?

Q. What is the boiling point of acetic acid?

Q. Dilute Sulphuric acid is a good conductor of electricity. State True or False

1. True
2. False

Q.

What is the mass of nitrogen in 1000 kg of urea [CO(NH₂)₂]?
(H = 1; C = 12; N = 14; O = 16)

Q.

Acids change the colour of methyl orange to:

1. Blue

2. Purple

3. Colourless

4. Pink/Red

Q.

Empirical formula of a compound is CH₂O. If its empirical formula mass is equal to its vapour density. Calculate the molecular formula of the compound.

Q. What is the boiling point of Nitric Acid ?

1. 70 degree celsius
2. 90 degree celsius
3. 86 degree celsius
4. 88 degree celsius

Q. Is the ethyne carbanion more stable than benzylic and allylic carbanion?

Q.

Nitric acid obtained in the laboratory is slightly yellow. The yellow colour of the acid is removed by addition of excess of oxygen gas.

1. True

2. False

Q.

How do alcohols differ structurally from alkanes?

Q. ntThe mass of carbon present in 0.1 mol of sodium ferricyanide is equal to :n ntA) mass of C present in 0.6 g-molecule of CO2n ntB) mass of magnesium in 0.3 mol of MgSO4n ntC) mass of C in 0.05 mol of sucrosen ntD) all of thesen

Q.

Pure nitric acid is colourless but the acid obtained in the laboratory is slightly yellow. The yellow colour is due to___.

1. The dissolution of NO in the acid.

2. The dissolution of N₂O in the acid.

3. The dissolution of NO₂ in the acid.

4. The dissolution of N₂O₅ in the acid.

Q. State, what is observed when nitric acid is kept in a reagent bottle for a long time.