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Chemistry 10th Class Chapter 20 Water Test 6 | New Syllabus 2027
Grade 10 Chemistry Chapter 20 Water Topic Covered 20.6 to 20.10
Prepare for the Punjab Board Class 10 Chemistry Examination 2027 with Chapter 20: Water – Class Test No. 6. This test covers textbook topics 20.6 to 20.10 and is designed to help students revise important concepts and assess their understanding of the Water chapter. As part of our Punjab Board 2027 Chemistry Model Papers and Chapter-Wise Test Series, this practice test supports exam preparation according to the new syllabus issued by PECTAA Punjab. Attempt this Class 10 Chemistry test to strengthen your subject knowledge, improve your preparation, and build confidence for the 2027 annual board examinations.
Chapter Wise Class Test
T-6
Chapter-20
Water
1.How many people suffer from water-borne diseases every year globally?
(a) 100 million(b) 300 million(c) 500 million(d) 800 million
Ans: (b) 300 million
2.Water pollutants disrupt aquatic ecosystems primarily through:
(a) Eutrophication(b) Photosynthesis(c) Distillation(d) Condensation
Ans: (a) Eutrophication
3.In Southern Pakistan, the annual precipitation is typically:
(a) Above 500 mm(b) Exactly 400 mm(c) Below 200 mm(d) Between 300-400mm
Ans: (c) Below 200 mm
4.To face the effects of climate change, we should take:
(a) No action(b) Appropriate measures(c) More flood irrigation(d) None of these
Ans: (b) Appropriate measures
5.Adding too much of which type of nutrient can be “poisonous” or dangerous to plant growth?
(a) Macro-nutrients(b) Micro-nutrients(c) Water(d) Carbon dioxide
Ans: (b) Micro-nutrients
6.Nutrients in a fertilizer should be:
(a) Insoluble in water(b) Volatile(c) Water soluble(d) Gaseous
Ans: (c) Water soluble
7.Phosphatic fertilizers provide:
(a) Nitrogen(b) Phosphorus(c) Potassium(d) Calcium
Ans: (b) Phosphorus
8.Filteration is not sufficient to make water safe for drinking due to:
(a) It is slow(b) It removes only large particles(c) It does not kill microorganism(d) It changes taste
Ans: (c) It does not kill microorganism
(P.T.O)
Chapter Wise Class Test
T-6
Chapter-20
Water
2. Write short answers to any six (6) questions.
[6 × 2 = 12]
(i)Why is the disease ‘trachoma’ a serious concern in developing countries?
Ans: Trachoma is an eye infection caused by bacteria and spread by dirty water, poor hygiene and flies. In developing countries clean water and sanitation are scarce, so it spreads widely and can lead to permanent blindness.
(ii)Why is Pakistan included in a semi-arid region?
Ans: Most of Pakistan receives very low annual rainfall (below 250 mm in many areas, and below 200 mm in the south) with high evaporation and hot dry weather, so it is classified as semi-arid.
(iii)How can we address the problem of water scarcity?
Ans: By building dams and reservoirs, conserving and recycling water, avoiding wastage, lining canals to reduce seepage, using drip and sprinkler irrigation instead of flood irrigation, and spreading public awareness.
(iv)What are micro-nutrients? Write names of micro- nutrients.
Ans: Micro-nutrients are elements needed by plants in very small (trace) amounts. Examples: iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), boron (B), molybdenum (Mo) and chlorine (Cl).
(v)State three characteristics that make a fertilizer suitable for plants.
Ans:
- It should be water soluble so roots can absorb it.
- It should be non-toxic to plants.
- It should be stable, cheap and available, and contain the required nutrient in good percentage.
(vi)What is the role of nitrogenous fertilizers?
Ans: They supply nitrogen, which is needed for proteins, chlorophyll and vegetative growth. They make leaves green and increase crop yield.
(vii)What is the role of potassium fertilizers?
Ans: They supply potassium, which helps in enzyme activity, water balance and opening and closing of stomata. They improve disease resistance and the quality of fruits and grains.
(viii)Which pollutants are harmful for aquatic life?
Ans: Sewage, industrial waste, heavy metals (lead, mercury), pesticides, fertilizers (nitrates and phosphates), oil spills and detergents.
(ix)Which is the most concentrated solid nitrogen fertilizer?
Ans: Urea, CO(NH2)2, contains about 46% nitrogen.
Note: Attempt any one question.
[5 × 1 = 5]
3Why Pakistan face water scarcity? Explain it.
Ans: Pakistan faces water scarcity because of:
- Low rainfall: a semi-arid climate with high evaporation.
- Population growth: demand for drinking, farming and industry keeps rising.
- Climate change: melting glaciers and irregular monsoons.
- Poor management: few dams and reservoirs, so flood water is wasted.
- Wasteful irrigation: flood irrigation and seepage from unlined canals.
- Pollution: industrial and sewage waste makes water unusable.
4.Classify the elements essential for plant growth and describe micro-nutrients and macro-nutrients.
Ans: Essential elements are classified into:
- Non-mineral elements: carbon (C), hydrogen (H), oxygen (O), taken from air and water.
- Macro-nutrients: needed in large amounts. Primary: nitrogen (N), phosphorus (P), potassium (K). Secondary: calcium (Ca), magnesium (Mg), sulphur (S).
- Micro-nutrients: needed in trace amounts: iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), boron (B), molybdenum (Mo), chlorine (Cl). Too much of them can be toxic to plants.
