Two students X and Y report the mass of the some substances as 7.0 g 7.00 g respectively. Which one of the student is more accurate?
Avogadro’s hypothesis states that
Which of the following concentration term is independent of temperature?
In a mole of water vapour at NTP, the volume actually occupied or taken up by the molecules is
If the oxides of a metal contain 78.7% and 64.5% of oxygen and if the formula of the first oxides is MO, find the formula of other oxide, the ratio of oxygen in two oxides is 1:3.
a. State avogadro law
b. What is the mass of 1 L of mercury in grams and in kilograms, 1 d the density of liquid mercury in grams is 13.6gcm3?
a. How many atoms are present in 1 ml of NH3 at STP?
b. Calculate the number of atoms present in 1.4 g of N2
a. An atom is 16 times heavier than 1/2 of mass of a carbon atom (C-12 isotope). What is its mass in amu?
b.Why do atomic masses of most of the elements in atomic mass units involve fractions?
a. How many significant figures are in each of the following numbers?
i. 003
ii. 6.02×1023
b. Round each of the following numbers to three significant figures.
a. 0.30 mole Zinc are added to hydrochloric acid containing 0.52 mole HCI. How many moles of H2 are produced?
b. Identify the limiting reagent in the above reaction.
A given solution of NaOH contains 2.00 g of NaOH per litre of solution. Calculate the morality of this solution?
b. Define molality
The chemical compounds are represented by both empirical and Molecular formula. A very popular organic compount is a major constituent of alcoholic drinks.
a. What is the molecular formula of the compound?
b. Find the percentage composition of the compound.
One molecule of methane contains five atoms. How many electrons are present in 0.16 g of methane?
i. Classify the following substances into elements compounds and mixtures. In case of mixture indicate whether the mixture is homogeneous or heterogeneous.
a. steel
b. mercury
c. diamond
d. sucrose
e. sodium chloride
f. smoke
ii. How do homogeneous mixture differ from heterogeneous?
Nitrogen forms various oxides as given below:
a. Identify the law of chemical combination illustrated by these data?
b. Determine the formula of each ratio from the given data. (Hint: Formula of first oxide is NO)
| Oxides | Mass of N2(g) | Mass of O2(g) |
| oxide I | 14 | 16 |
| oxide II | 14 | 32 |
| oxide III | 28 | 16 |
| oxide Iv | 28 | 48 |
“One mole of all substances contain the same number of specified particles”.
a. Justify the statement.
b. What is the relation between mole and volume?
A compound contains 54.54% carbon. 9.09% Hydrogen and 36.36% oxygen. Its molar mass is 88. What are its empirical and molecular formula?
A person suffering from urolithiasis is advised by a doctor to take 20 glasses of water daily. Assuming one glass of water contains 180 ml, calculate the number of moles and molecules of water consumed daily by the patient.
(Hint: density of water = 1 g/ml)
A mixture of 1 mol of Al and 3 mol of Cl2 are allowed to react as 2AI(s)+ 3CI2(g)-2AICI3
a. How many moles of AICI3 are formed?
b. Identify the limiting reagent.
c. How many moles of excess reactant left unreacted?
