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Worksheetsscience competency based cbse quizz
Total questions: 49
Worksheet time: 25mins
The substance not likely to contain CaCO3 is
Dolomite
A marble statue
Calcined gypsum
Sea shells.
A student added 10g of calcium carbonate in a rigid container, secured it tightly and started to heat it. After some time, an increase in pressure was observed, the pressure reading was then noted at intervals of 5 mins and plotted against time, in a graph as shown below. During which time interval did maximum decomposition took place?
15-20 min
10-15 min
5-10 min
0-5 min
Gas A, obtained above is a reactant for a very important biochemical process which occurs in the presence of sunlight. Identify the name of the process -
Respiration
Photosynthesis
Transpiration
sphotolysis
Marble statues are corroded or stained when they repeatedly come into contact with polluted rain water. Identify the main reason.
decomposition of calcium carbonate to calcium oxide
polluted water is basic in nature hence it reacts with calcium carbonate
polluted water is acidic in nature hence it reacts with calcium carbonate
calcium carbonate dissolves in water to give calcium hydroxide.
Calcium oxide can be reduced to calcium, by heating with sodium metal. Which compound would act as an oxidizing agent in the above process?
Sodium
sodium oxide
calcium
calcium oxide
The chemical reaction between MnO2 with HCl is depicted in the following diagram. It was observed that a gas with bleaching abilities was released.
displacement reaction
combination reaction
redox reaction
decomposition reaction.
Chlorine gas reacts with _______ to form bleaching powder.
dry Ca(OH)2
dil. solution of Ca(OH)
conc. solution of Ca(OH)
dry CaO
Identify the correct statement from the following:
MnO2 is getting reduced whereas HCl is getting oxidized
MnO2 is getting oxidized whereas HCl is getting reduced.
MnO2 and HCl both are getting reduced.
MnO2 and HCl both are getting oxidized.
In the above discussed reaction, what is the nature of MnO2?
Acidic oxide
Basic oxide
Neutral oxide
Amphoteric oxide
What will happen if we take dry HCl gas instead of aqueous solution of HCl?
Reaction will occur faster.
Reaction will not occur.
Reaction rate will be slow
Reaction rate will remain the same.
Which of the following are the products obtained from the reaction mentioned in the above case?
CO2 H2O
H2O CO
CH3OH H2O
CO2 H2O
Identify the types of chemical reaction occurring during the combustion of fuel:
Oxidation & Endothermic reaction
Decomposition & Exothermic reaction
Oxidation & Exothermic reaction
Combination & Endothermic reaction
On the basis of evolution/absorption of energy, which of the following processes are similar to combustion of fuel?
Photosynthesis in plants
Respiration in the human body
Decomposition of vegetable matter
Decomposition of ferrous sulphate.
Choose the correct reason for the production of black smoke:
Limited supply of air leads to incomplete combustion of fuel.
Rich supply of air leads to complete combustion of fuel.
Rich supply of air leads to a combination reaction.
Limited supply of air leads to complete combustion of fuel.
Identify the correct reason for the statement: 'Although nitrogen is the most abundant gas in the atmosphere, it does not take part in combustion'.
Nitrogen is a reactive gas
Nitrogen is an inert gas
Nitrogen is an explosive gas
Only hydrocarbons can take part in combustion
Predict the pH value of the water of river Yamuna if the reason for froth is high content of detergents dissolved in it.
10-11
5-7
2-5
7
Which of the following statements is correct for the water with detergents dissolved in it?
low concentration of hydroxide ion (OH-) and high concentration of hydronium ion (H3O+)
high concentration of hydroxide ion (OH-) and low concentration of hydronium ion (H3O+)
high concentration of hydroxide ion (OH-) as well as hydronium ion (H3O+)
equal concentration of both hydroxide ion (OH-) and hydronium ion (H3O+).
Which of the following correctly represents the solutions in increasing order of their hydronium ion concentration?
P>Q>R>S
P>S>Q>R
S
S
High content of phosphate ion in river Yamuna may lead to:
decreased level of dissolved oxygen and increased growth of algae
decreased level of dissolved oxygen and no effect of growth of algae
increased level of dissolved oxygen and increased growth of algae
decreased level of dissolved oxygen and decreased growth of algae
If a sample of water containing detergents is provided to you, which of the following methods will you adopt to neutralize it?
Treating the water with baking soda
Treating the water with vinegar
Treating the water with caustic soda
Treating the water with washing soda
In which of the parts would you find anaerobic bacteria?
A
B
C
D
Which one of the following is NOT correct for biogas?
its carbon neutral
its non-renewable
it depends on micro-organisms
yields rich manure
Which of the following best indicates the steps of anaerobic digestion?
Waste water feed → biogas storage → generator → biogas
Waste water feed → digester → biogas → biogas storage → generator
Generator → waste water feed → digester → biogas → biogas storage
Waste water feed → biogas → digester → biogas storage → generator
Biogas is a better fuel than animal dung cake because
Biogas is a renewable source of energy
Animal dung cake has higher calorific value
Biogas has high heating capacity
Biogas burns without smoke.
Biogas is formed in the
presence of air only
presence of water only
presence of air and absence of water
presence of water and absence of air.
If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy?
10,000 J
100 J
1000 J
It will depend on the type of the terrestrial plant.
If Ravi is consuming curd/yogurt for lunch, which trophic level in a food chain he should be considered as occupying?
First trophic level
Second trophic level
Third trophic level
Fourth trophic level
The decomposers are not included in the food chain. The correct reason for the same is because decomposers:
Act at every trophic level of the food chain
Do not breakdown organic compounds
Convert organic material to inorganic forms
Release enzymes outside their body to convert organic material to inorganic forms
Matter and energy are two fundamental inputs of an ecosystem. Movement of
Energy is bidirectional and matter is repeatedly circulating.
Energy is repeatedly circulation and matter is unidirectional.
Energy is unidirectional and matter is repeatedly circulating.
Energy is multidirectional and matter is bidirectional.
Which of the following limits the number of trophic levels in a food chain?
Decrease in energy at higher trophic levels
Less availability of food
Polluted air
Water
The mussel can be described as
Producer
Primary consumer
Secondary consumer
decomposer
Which trophic level is incorrectly defined?
Carnivores – secondary or tertiary consumers
Decomposers – microbial heterotrophs
Herbivores – primary consumers
Omnivores – molds, yeast and mushrooms
The given figure best represents:
Grassland food chain
Parasitic food chain
Forest food chain
Aquatic food chain
Why do all food chains start with plants?
Because plants are easily grown
Because plants are nutritious
Because plants can produce its own energy
Because plants do not require energy
In the food web, what two organisms are competing for food?
A and B
D and F
A and C
B and D
Choose the waste management strategy that is matched with correct example.
Refuse
Reduce Give unwanted toys and books to hospitals or schools
Reuse
Repurpose
Recycling of paper is a good practice but recycled paper should not be used as food packaging because
recycled papers may release color /dyes on food items
recycled papers are not absorbent
recycled papers can cause infection due to release of methane
recycled papers are costly
According to the ‘Solid Waste Management Rule 2016’, the waste should be segregated into three categories. Observe the table below and select the row that has correct information.
Cooked food, vegetable peels; Used bulbs, fluorescent lamps; Plastic carry bags, bottles, newspaper, cardboard
Coffee and tea powder, garden waste; Plastic carry bags, bottles, newspaper, cardboard; Expired medicines, razors, paint cans
Leftover food, vegetable peels; Coffee and tea powder, garden waste; Insect repellents, cleaning solutions
Uncooked food, tea leaves; Old crockery, frying pans; Coffee and tea powder, garden waste
Effective segregation of wastes at the point of generation is very important. Select the appropriate statements giving the importance of waste segregation.
both i) and ii)
both i) and iii)
both ii) and iii)
both i) and iv)
When recycling a plastic water bottle, what should you do with the cap?
The cap goes into a garbage can and the bottle goes in a recycling bin
Screw the cap back on the bottle, then put the bottle and cap in a recycling bin
Screw the cap back on the bottle, then put the bottle and cap in the garbage can
Recycle the cap separately.
Biogas is formed in the
presence of air only.
presence of water only.
absence of air only.
presence of water and absence of air.
If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy?
10,000 J
100 J
1000 J
It will depend on the type of the terrestrial plant.
Mr. X is eating curd/yogurt. For this food intake in a food chain he should be considered as occupying
First trophic level
Second trophic level
Third trophic level
Fourth trophic level
The decomposers are not included in the food chain. The correct reason for the same is because decomposers:
Act at every trophic level of the food chain
Do not breakdown organic compounds
Convert organic material to inorganic forms
Release enzymes outside their body to convert organic material to inorganic forms
Choose the waste management strategy that is matched with correct example.
Refuse: Choose products that use less packaging
Reduce: Give unwanted toys and books to hospitals or schools
Reuse: Not using single use plastic
Repurpose: Making flower pot from used plastic bottle
Recycling of paper is a good practice but recycled paper should not be used as food packaging because
recycled papers take lots of space
recycled papers can’t cover food properly
recycled papers can cause infection
recycled papers are costly
According to the ‘Solid Waste Management Rule 2016’, the waste should be segregated into three categories. Observe the table below and select the row that has correct information.
Cooked food, vegetable peels; Used bulbs, fluorescent lamps; Plastic carry bags, bottles, newspaper, cardboard
Coffee and tea powder, garden waste; Plastic carry bags, bottles, newspaper, cardboard; Expired medicines, razors, paint cans
Leftover food, vegetable peels; Coffee and tea powder, garden waste; Insect repellents, cleaning solutions
Uncooked food, tea leaves; Old crockery, frying pans; Coffee and tea powder, garden waste
Effective segregation of wastes at the point of generation is very important. Select the appropriate statements giving the importance of waste segregation.
both i) and ii)
both i) and iii)
both ii) and iii)
both i) and iv)
Who is the Imposter ?
A
B
C
D
