very imp questions
1 Where will the image be formed by concave mirror when an object is placed between the pole and the focus point of the mirror ? [1]
2 Allotropy is a property shown by which class of substances, elements, compounds or mixtures?
Give one example of allotropy. [2]
3. With respect to air the refractive indices of water and benzene are 1.33 and 1.50
respectively. Calculate the refractive index of benzene with respect to water. [2]
4. (a) Write the chemical equation representing the reaction for the preparation of methanal from methanol.
(b) What happens when methanal is mixed with :
(i) Ammoniacal silver nitrate solution and the mixture is warmed.
(ii) Fehling's reagent and the mixture is warmed.
(c) Complete the reaction equation :
H
|
H—C=O + HCN [3]
Or
Write the formulae for the given compounds and name the functional groups
present in each of them :
(i) Ethanoic acid (ii) Propanone (iii) Nitromethane
5 (a) Explain the following terms used in relation to defects in vision and corrections provided for them—
(i) Myopia (ii) Astigmatism (iii) Bifocal lenses (iv) Far sightedness.
(b) Describe with a ray diagram how a person with myopia can be helped by
6. Differentiate between 'self pollination' and 'cross pollination'. Describe 'double fertilisation' in plants.
7. What is 'organic evolution' ? How do embryological studies provide evidence for evolution ? [3]
Comments
Post a Comment