30 g of magnesium and 30 g of oxygen are reacted, then the residual mixture contains
60 g of magnesium oxide only
40 g of magnesium oxide and 20 g of oxygen
45 g of oxygen and 15 g of magnesium oxide
50 g of magnesium oxide and 10 g of oxygen
A 100 mL solution of 0.1 N HCl was titrated with 0.2 N NaOH solution. The titration was discontinued after adding 30 mL of NaOH solution. The remaining titration was completed by adding 0.25 N KOH solution.What is the volume of KOH required for completing the titration ?
70 mL
32 mL
35 mL
16 mL
The total number of electrons present in 18 mL of water (density of water is 1 gmL-1) is
6.02 × 1023
6.02 × 1024
6.02 × 1025
Rearrange the following (I to IV) in the order of increasing masses and choose the correct answer (atomic mass: O = 16, Cu = 63, N = 14)
I. 1 molecule of oxygen
II. 1 atom of nitrogen
III. 1 × 10-10 g molecular weight of oxygen
IV. 1 × 10-10 g molecular weight of copper
II < I < III < IV
IV < III < II < I
II < III < I < IV
III < IV < I < II
One mole of calcium phosphide on reaction with excess of water gives
One mole of phosphine
Two moles of phosphoric acid
Two moles of phosphine
One mole of phosphorous pentoxide
How much of NaOH is required to neutralise 1500 cm3 of 0.1 N HCl ? (Na = 23)
40 g
4 g
6 g
60 g
Assuming that the density of water to be 1g/cm3, calculate the volume occupied by one molecule of water
2.989 × 10-23 cm3
6.023 × 1023 cm3
22400 mL
18 cm3
What is the percentage of water of crystallisation in a sample of blue vitriol ?
34.07%
35.07%
36.07%
37.07%
3 g of an oxide of a metal is converted to chloride completely and it yielded 5 g of chloride. The equivalent weight of the metal is:
3.325
33.25
12
20
A metal oxide contains 53% metal and carbon dioxide contains 27% carbon. Assuming the law of reciprocal proportions, the percentage of metal in the metal carbide is
75
25
37
66
