Question

QUESTION 19 10 p Which one of the following is not a soluble compound in water? O KOH O CaSO4 Li3PO4 O Mg(NO312 QUESTION 20 Which one of the following chemical equations is a balanced equation? CH4(E) + O2(g) - CO2(g) + H2008) HCl(aq) + HE2(NO3)2(aq) - He2Cl2ls1 + HNO3(aq) 2NH4Cl(aq) + Pb(NO3)2(aq) - PbCl215) + NH4NO3(aq) 2C3H6tel + 9 020) - 6CO2(g) + 6H2008) Save hle Sone All Answers to save all answers.

Answer 1

Q11. Molar mass of NH₃ = 17 g/mol

  $\therefore$ 25.5 g ammonia = (25.5 g / 17 g/mol) = 1.5 mol

1 mol of NH₃ contains 3 mols of H atom

  $\therefore$ 1.5 mol of NH₃ contains (1.5 * 3) = 4.5 mols of H atom

So, the correct anmswer is 'Fourth option'.

Q12. Molar mass of Mg(NO₃)₂ = 148.3148 g/mol

Atomic mass of Mg = 24.305 g/mol

$\therefore$ % composition of Mg = %

24.305 148.314 * 100 = 16.38

  So, the correct anmswer is 'Second option'.

Q13. 1.651 g Ag = (1.651 g / 108 g/mol) = 0.015 mol

0.1224 g O = (0.1224 g / 16 g/mol) = 7.65*10^-3 mol

Now, Ag : O = 0.015 : 7.65*10^-3 = 2 : 1

  $\therefore$ The formula of the compound is Ag₂O.

  So, the correct anmswer is 'Third option'.

Q14. Assume we have 100 g of the compound. Then we have 75.69 g of C ; 8.8 g of H and 15.51 g O.

Moles of C= (75.69 g / 12 g/mol) = 6.3075 mol

Moles of H= (8.8 g / 1 g/mol) = 8.8 mol

Moles of O = (15.51 g / 16 g/mol) = 0.97 mol

Now, C : H : O = 6.3075 : 8.8 : 0.97 = 6.5 : 9 : 1

$\therefore$ The formula of the compound is C_6.5H₉O.

Q15. CuCl₂(aq) + Zn(s) →ZnCl₂(aq) + Cu(s)

This is an example of 'single replacement' reaction.