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1.BASIC CONCEPTS                                                   eLearn.Punjab

Q.10 Calculate each of the following quantities.  •	 (Ans: 432.92g)
                                                  •	 (Ans: 0.36 mole)
a)	 Mass in grams of 2.74 moles of KMnO4.         •	 (Ans: 2.18 x 1023 atoms)
b)	 Moles of O atoms in 9.00g of Mg (N03)2.       •	 (Ans: 2.70x10-5 kg)
c)	 NumberofOatomsin10.037gofCUSO4.5H2O.          •	 (Ans: 0.0178 moles)
d)	 Massinkilogramsof2.6x1020moleculesofSO2.      •	 (Ans: 1416.2 g)
e)	 Moles of Cl atoms in 0.822 g C2H4Cl2.         •	 (Ans: 0.7158 g)
f)	 Mass in grams of 5.136 moles of Ag2CO3.       •	 (Ans: 0.816 moles, 4.91 x 1023 formula units)
g)	 Mass in grams of 2.78 x 1021 molecules of
                                                  •	 (Ans:4.91x1023K+,4.91x1023CIO3-1,4.91x1023
    CrO2Cl2.                                         Cl-1,1.47x 1024 O atoms)
h)	 Numberofmolesandformulaunitsin100gof

    KClO3.
i)	 NumberofK+ions,CIO-3ions,Clatoms,and O

    atoms in (h).

Q.11 Aspartame, the artificial sweetner, has a molecular formula of C14H18N2O5.
a)	 What is the mass of one mole of aspartame?					 (Ans: 294 g mol-1)
b)	 How many moles are present in 52 g of aspartame?				 (Ans:	0.177	mole)
c)	 What is the mass in grams of 10.122 moles of aspartame?				 (Ans:	2975.87
d)	 How many hydrogen atoms are present in 2.43 g of aspartame?(Ans: 8.96 x 1022 atoms of H)

Q.12 A sample of 0.600 moles of a metal M reacts completely with excess of fluorine to form 46.8 g of MF2.

a)	 How many moles of F are present in the sample of MF2 that forms? 	 (Ans: 1.2 moles)

b)	 Which element is represented by the symbol M?	                 	 (Ans:	calcium)

Q.13 In each pair, choose the larger of the indicated quantity, or state if the samples are equal.

a)	 Individual particles: 0.4 mole of oxygen molecules or 0.4 mole of oxygen atoms.

	 (Ans: both are equal)

b)	 Mass: 0.4 mole of ozone molecules or 0.4 mole of oxygen atoms. 	 	                (Ans: ozone)

c)	 Mass: 0.6 mole of C2H4 or 0.6 mole of I2.                        	                (Ans: I2)
d)	 Individual particles: 4.0 g N2O4 or 3.3 g SO2.                 		                 (Ans: SO2)
e)	 Total ions: 2.3 moles of NaCIO3 or 2.0 moles of MgCl2.         		                 (Ans: MgCl2)
f)	 Molecules: 11.0 g H2O or 11.0 g H2O2.                                             (Ans:H2O)
g)	Na+ ion: 0.500 moles of NaBr or 0.0145 kg of NaCl.               		                (Ans: NaBr)
                                                                    		

h)	 Mass: 6.02 x 1023 atoms of 235U or 6.02 x 1023 atoms of 238U.  		                 (Ans: U238)

Q.14 a) Calculate the percentage of nitrogen in the four important fertilizers i.e.,

(i) NH3  (ii) NH2CONH2(urea)  (iii) (NH4)2SO4                          (iv) NH4NO3.
                                                                   (Ans: 82.35%, 46.67%, 21.21%, 35%)

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