CIE Chemistry Paper-1: Specimen Questions 27 - 28 of 99
Question number: 27
The chemical formulae of two substances, W and X, are given.
W NaAl Si3O8
Which statements are correct?
1 W and X contain the same amount of oxygen.
2 W contains three times as much silicon as X.
3 X contains twice as much aluminium as W.
2 and 3
|b.||1 and 2|
1 and 3
1, 2 and 3
It can be seen that both the substance contains same amount of Oxygen i. e O8 and W have one Al atom whereas X have 2.
Question number: 28
Which diagram does not show the outer shell electrons in the molecule correctly?
As we know the atomic no of chlorine is 17
Electronic configuration will be 2, 8, 7. That means 7 electrons will be there in the outer most shell of the atom. In figure 4 one Cl satisfies the no of electrons whereas the other has only one left in the outer most shell.