Question Text
Question 5 :
The mass of one steel screw is 4.11g. Find the mass of one mole of these steel screws. Compare this value with the mass of the Earth ($5.98\times 10^{24}$). Which one of the two is heavier and by how many times?
Question 8 :
Which postulate of Dalton’s atomic theory can explain the law of definite proportions?
Question 12 :
If one mole of carbon atom weighs 12 g, what is the mass (in gram) of 1 atom of carbon?
Question 13 :
Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12 g. Molar atomic mass of magnesium is $24g mol^{-1}$.
Question 18 :
What is the SI prefix for $10^{-2}$ multiples and submultiples of a unit?
Question 22 :
What is the metal which exists in the liquid state at room temperature?
Question 26 :
Give the formulae of the compounds formed from sodium and oxygen.
Question 28 :
When 3.0 g of carbon is burnt in 8.0 g of oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.0 g of oxygen?
Question 29 :
The visible universe is estimated to contain $10^{22}$ stars. How many moles of stars are present in the visible universe?
Question 32 :
A silver ornament of mass ‘m’ gram is polished with gold equivalent to $1\%$ of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
Question 35 :
Compute the ratio by mass of the combining elements for Aluminium Fluoride.
Question 40 :
What is the element used by Rutherford during his $\alpha$ - scattering experiment?