Some Basic Conc...

Calculate the weight of lime (CaO) obtained by heating 200 kg of 95% pure limestone (CaCO₃).

20 m/s is the same as:

30.4 cm  = ---------- mm.:

Two students X and Y report the mass of the same substance as 7.0 g and 7.00 g, respectively. Which of the following statements is correct?

We have to prepare a Litre solution of 0.2 M NaOH from the available 1 M solution.

What volume of 1M NaOH is required to be taken ?

In centigrade scale, -40 °F becomes

The haemoglobin of most mammals contains approximately 0.33% of iron by mass. The molecular mass of haemoglobin is 67200. The number of iron atoms in each molecule of haemoglobin is

Consider the chemical reaction given as,

-----CO (g) + ----- H₂(g) → ----- C₈H₁8(l) + ----- H₂O.

This equation can be balanced by inserting the following in blank spaces

A mixture of CaCl₂ and NaCl weighing 4.44 g, when treated with sodium carbonate solution, precipitates all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get 0.56 g of CaO.

The % of NaCl in the mixture is 

An object travels with a speed of 96 miles per hour. What is the speed of the object in SI units?

A mixture of ethane and ethene occupies 41 L at 1 atm and 500 K. The mixture reacts completely with 10/3 moles of O₂ to produced CO₂ and H₂O. The mole fractions of ethane and ethene in the mixture respectively are ( R = 0.082 L atm mol^-1)

Phosgene, a poisonous gas used during World War – I, contains 12.1% C, 16.2% O and 71.7% Cl by mass. What is its empirical formula?

A certain gaseous mixture contains methane and sulphur dioxide in the ratio 1 : 8 by mass. The ratio of numbers of molecules is

Which of the following sets of compounds correctly illustrates the law of reciprocal proportion?

On dividing 0.86 by 16.564, the actual answer is 0.0519198. The correctly reported answer will be

If 6 x 10²⁰ molecules of CO₂ are removed from 220 milligrams of CO₂, what is the number of remaining moles of CO₂?

Two samples of sodium chloride are produced when sodium combines separately with two isotopes of chlorine ³⁵Cl and ³⁷Cl.

Which law is illustrated by the above facts?

Calculate the numbers of Cl^- and Ca²⁺ ions in 222 g of anhydrous CaCl₂.

If we consider that 1/6 in place of 1/12 mass of carbon atom is taken to be relative atomic mass unit, then the mass of one mole of a substance will

How many grams of concentrated nitric acid solution should be used to prepare 250 ml of 2.0 M HNO₃? The concentrated acid is 70% HNO₃.

There are ____ cms. in 0.101 mm.?

15 km is  =   ---------------- m.?

How many years would it take to spend Avogadro's number of rupees at the rate of million rupees per second?

30 microliters is the same as:

Which of the following best explains the law of conservation of mass?

Three flasks of equal volumes contain CH₄, CO₂ and Cl₂ gases. They will contain equal number of molecules if 

20 grams is the same as:

Two oxides of a metal contain 36.4% and 53.4% of oxygen by mass. If the formula of the first oxide is M₂O, then that of the second is 

If 25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a value of 35 ml, the molarity of barium hydroxide solution was 

There are ___ L  in 12.0 ml?