first year chemistry notes chap#1 lahore board

ACADEMY FOR EXCELLENCE LHR

Chemistry-1^st 09-10 Ch# 1  (C , E)                                            Paper: Complete Without Prob of Exercise                                               Total Marks: 20

Name: ______________________________________________________Sec: ______________Roll: _________________

A.         Choose the correct answer

1.            Atoms of which gas can exist independently  

                                a. O₂                                       b. CO₂                    c. Ar                       d. N₂

2.            There are many examples of anions having group of atoms like

                                a. PO(3–)₄                                   b. Cl(–)                       c. P(–)                         d. S(–2)

3.            Carbon is used as standard reference for relative atomic mass due to

                                a. unstability of carbon                                b. stability of carbon

                                c. abundance of carbon compounds      d. both b + c

4.            Which of the following statement is true for mass spectrometer

a. It uses liquid molecules in magnetic field

b. Magnetic field supply the voltage to vapours

c. It separates Ions according to their mass only

d. All Statements are wrong

5.            By combustion analysis, only those organic compounds can be analyzed which simply contain

                                a. C , S , N                             b. C , H , O            c. C , H , N            d. S , H , O

6.            Which statement about molar volume is true?

                                a. it is denoted  by Vm   b. It is applicable only to an ideal gas

                                c. normally in gases, one molecule is about 300 times at a greater distance

                                  than its own diameter

d. All are true

7.            The mass of one mole of electrons is

                                a. 1.008 mg                        b. 0.55 mg                           c. 0.184 mg        d. 1.673 mg

8.            The number of moles of CO₂, which contain 8.0 g of oxygen

                                a. 0.25                                  b. 0.50  c. 1.0                     d. 1.50

9.            One mole of SO₂ contains

                                a. 6.02 x 10²³ atoms of oxygen b. 18.1 x 10²³molecules of SO­₂

                                c. 2 x 6.02²³ atoms of sulphur    d. 2 x 6.02²³ atoms of oxygen

10.          One atom mass unit is equal to

                                a. 1.66 x 10^–27 kg              b. 1.66 x 10^–27 g                c. 1.66 x 10^–24 g                d. Both a + c

Give Short Questions                                                                                                                                                              

a). Why we use limiting reactant deliberately

B). What is Gram molecule. Give two examples

Q#2.     Explain in detail mass spectrometry