Advertisements
Advertisements
Question
If the relative molecular mass of A is 90, what is the molecular formula of A?
Advertisements
Solution
The relative molecular mass of A is 90
Empirical Formula mass of compound is = 45
Then, n = Molecular mass/ Empirical Formula Mass
= 90/45 = 2
Molecular formula of compound = n x Empirical formula
= 2 x (CO2H) = C2O4H2.
APPEARS IN
RELATED QUESTIONS
Calculate the percentage composition of oxygen in lead nitrate [Pb(NO3)2]. [Pb = 207, N= 14, O = 16]
Concentrated nitric acid oxidizes phosphorous to phosphoric acid according to the following equation :
P + 5HNO3 → H3PO4 + H2O + 5NO2
What mass of phosphoric acid can be prepared from 6 .2 g of phosphorous?
Calculate the percentage of phosphorous in the fertilizer superphosphate, Ca(H2PO4)2. [Ca = 40, H =1, P =31, O = 16] (Correct to 1 decimal place)
When heated, potassium permanganate decomposes according to the following equation:
\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]
Given that the molecular mass of potassium permanganate is 158 g, what volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres). [K = 39, Mn = 55, O = 16]
What is the vapour density of ethylene? (Avogadro's number = 6 x 1023; Atomic weight of C = 12, H = 1; Molar volume = 22.4 litres at STP)
A compound 'X' consists of 4.8% of C and 95.2% of Br by mass.
If the vapour density of the compound is 252, what is the molecular formula of the compound?
Which of the following would weigh most?
Calculate the number of hydrogen atoms in 0.1 mole of H2SO4.
Calculate the mass of nitrogen supplied to soil by 5 kg of urea [CO(NH2)2].
[O = 16; N = 14; C = 12; H = 1]
When heated, potassium permanganate decomposes according to the following equation :
\[\ce{2KMnO4 -> \underset{\text{solid residue}}{K2MnO4 + MnO2} + O2}\]
(a) Some potassium permanganate was heated in the test tube. After collecting one litre of oxygen at room temperature, it was found that the test tube had undergone a loss in mass of 1.32 g. If one litre of hydrogen under the same conditions of temperature and pressure has a mass of 0.0825 g, calculate the relative molecular mass of oxygen.
(b) Given that the molecular mass of potassium permanganate is 158. What volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres)
