Acid bases n salts

Question 1

H2SO4

Answer 1

sulphuric acid

Question 2

H2CO3

Answer 2

carbonic acid

Question 3

NAOH is strong or weak base

Answer 3

STRONG

Question 4

Vinegar scientific name-

Answer 4

acetic acid

Question 5

What happens to hydrogen ions when lime juice is added to vinegar solution?

Answer 5

INCREASES as acetic acid+citric acid

Question 6

Magnifying glass is made of which lens

Answer 6

convex

Question 7

why concave lens cant magnify

Answer 7

We can observe that in a concave lens, the light beam coming from the source diverges, so the image formed will be virtual and diminished. Therefore, a concave lens cannot be used as magnifying glass.

Question 8

A concave mirror produces enlarged real image of an object placed at 8 cm in front
of it. Where is the image located ?
(a) At the centre of curvature
(b) At the principal focus
(c) Between centre of curvature and principal focus
(d) Beyond centre of curvature.

Answer 8

D…image

Question 9

Which of the following reaction is not correct?

(a) Zn + CuSO4→ ZnSO4 + Cu
(b) 2Ag + Cu(NO3)2→ 2AgNO3 + Cu
(c) Fe + CuSO4→ FeSO4 + Cu
(d) Mg + 2HCl → MgCl2 + H2

Answer 9

B

Question 10

What happens to hydrogen ions when lime juice is added to vinegar solution?

(a) increases
(b) decreases
(c) do not change
(d) none of the above

Answer 10

A

Question 11

Food cans are coated with tin, not with zinc because :

(a) Zinc is costlier than tin
(b) Zinc has a higher melting point than tin
(c) Zinc is more reactive than tin.
(d) Zinc is less reactive than tin

Answer 11

C

Question 12

baking soda eq

Answer 12

NaCl (aq) + NH3 (aq) + CO2 (g) + H2O (l) → NaHCO3 (aq) + NH4Cl (aq)

Question 13

An element reacts with oxygen to give a compound with a high melting point . This compound
is soluble in water . The element is likely to be
(a) Calcium (b) Carbon (c) Silicon (d) Iron

Answer 13

A- calcium hydroxide is formed

Question 14

PbS reacts with Ozone (O3) and forms PbSO4. As per the balanced chemical equation,
molecules of Ozone required for every one molecule of PbS is/are
(a) 4 (b) 3 (c) 2 (d) 1

Answer 14

A

Question 15

The inner side of guard cells is

(a) rough
(b) straight
(c) concave
(d) convex

Answer 15

concave

Question 16

why is stomata on the lower epidermis

Answer 16

The stomata must be open during the daylight hours to let oxygen and carbon dioxide pass through. … Transpiration is the loss of water through stomata, so, more stomata are found on the lower surface to prevent excessive loss of water.