Answer: (C)
Explanation :
It’s a reaction between sodium sulphate and barium chloride and the product is barium sulphate which is whitish in colour and remain insoluble.
Answer: (a)
Explanation:
(Alkaline sodium Hydroxide )
(Alkaline Potassium Hydroxide)
Answer: (d)
Explanation:
Hydrogen gas produces popping sound.
Answer: (b)
Option | Natural Source | Acid Present |
---|---|---|
(i) | Orange | Oxalic acid |
(ii) | Sour milk | Lactic acid |
(iii) | Ant sting | Methanoic acid |
(iv) | Tamarind | Acetic acid |
Answer: (c)
Explanation : Orange contains citric acid and tamarind contains tartaric acid.
Answer: (c)
Explanation : It’s the oxidation of food to produce energy means exothermic reaction (heat/energy liberated in the reaction).
Answer: (c)
Explanation :
(Oxidation number of Cl increases.)
(Oxidation number of Mn decreases.)
Ans: (d)
Explanation : Bases are bitter and turn red litmus blue. Bases have a pH more than 7
SL No. | Salt | Parent Acid | Parent Base | Nature of Salt |
---|---|---|---|---|
(a) | Solidum Chloride | NaOH | Basic | |
(b) | Sodium Carbonate | NaOH | Neutral | |
(c) | Sodium Sulphate | NaOH | Acidic | |
(d) | Sodium Acetate | NaOH | Basic |
Answer: (d)
Explanation - Sodium hydroxide is a strong base and salt formed will be basic.
Answer: (c)
Explanation - During a chemical reaction chemical composition changes.
Answer: (d)
Explanation : Blood vessel A represents pulmonary artery which is the only artery carrying deoxygenated blood to the lungs. Blood vessel B represents pulmonary veins which is the only vein carrying oxygenated blood from lungs to left atrium. The left atrium relaxes when it is collecting this blood and contracts to pump this blood to left ventricle.
Answer: (a)
Explanation:
Answer: (c)
Explanation : In unicellular organisms, diffusion across the cell membrane is sufficient for supplying oxygen to the whole body. Diffusion is a slow and passive process. Unicellular organisms can absorb sufficient oxygen because of its complete body contact with the surrounding environment.
Answer: (b)
Explanation : Any substance that oozes out from the pores of diseased or injured plant tissue is called as exudate. The process of oozing out of substances from plant is termed as exudation. Resins, gums, oils and water are examples of exudates widely extracted for industrial uses.
Answer: (d)
Explanation : Upon inhalation, the diaphragm contracts and flattens and the thoracic cavity or chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.
Answer: (c)
Explanation : The stomata are surrounded by two guard cells which regulate its opening and closing. Stomata are open during the day time for gaseous exchange and also release water vapour through transpiration. The opening and closing of stomata is due to the change in turgor pressure of the guard cell.
Answer: (a)
Explanation : In solar cooker, beam of sunlight falls on concave reflector which then focus/converge it on small cooking area at focal point.
Answer: (c)
Explanation - To get real & magnified image, object should be kept either between 2F and F or at F. If it is kept at F, image will form at infinity which cannot be taken on screen, so object should be kept between 2F and F.
Answer: (b)
Explanation - Here ray is passing though this device so it should be a lens. Also rays are diverging, so it should be a concave lens.
Answer: (b)
Explanation : We have to take ratio of higher refractive index to lower refractive index when light travels from one media to other media. Lower ratio shows lower deviation or vise-versa. Lowest ratio value will be for media A-B, so bending of light will be least.
Let refractive index of rarer medium be
Let refractive index of denser medium be
When ray travels from rarer to denser medium,
If is high, is larger than . So, which means deviation is high.
When ray travels from denser to rarer medium,
If is low, is larger than . So, which means deviation is high.
So, Air - A, ratio =
A - B, ratio = (smallest)
B - C, ratio =
C - air, ratio = (largest)
Answer: (c)
Explanation - Scattering has no relation with speed of light as all constituent colours travel with same speed.
Answer: (b) Sign — Positive, Value — More than 1
Explanation - When object is kept between F and P of concave mirror, image formed is virtual, erect and magnified. Location is behind the mirror, so magnification is more than 1 and positive.
Answer: (c)
Explanation - As we can see from diagram, light bends towards normal while passing from A to B, therefore . Now, it travels through B on straight path. As interface between A - B and between B - C are parallel, so are alternate interior angles and equal (). Now from B to C, light moves away from normal, so . Also, if we extend ray in medium A, we will see that it will intersect actual ray in C which shows that .
Answer: (c)
Explanation : As we know, in dispersion, red color deviates the least and violet color deviates the most, so Y is red which is also the colour used to paint the danger signals.
Answer: (d)
Explanation : Calcium carbonate on heating produces carbon dioxide gas and calcium oxide.
S. No. | Sample | pH Value |
---|---|---|
1 | Lemon Juice | 2.2 |
2 | Gastric Juice | 1.2 |
3 | Vinegar | 3.76 |
4 | Dil. Acetic acid | 3.0 |
The decreasing order of their H+ ion concentration is
Answer: (c)
Explanation – Lower pH value means higher H+ ions concentration.
Option | P | Q | Change observed in calcium hydroxide solution |
---|---|---|---|
(a) | gas | No Change | |
(b) | gas | No Change | |
(c) | gas | Turns milky | |
(d) | gas | Turns milky |
Answer: (d)
Explanation :
Answer: (c)
Explanation :
Answer: (b)
Explanation : Copper is more reactive than silver and magnesium is more reactive than aluminium.
Answer: (d)
Explanation:
Bleaching powder – CaOCl2
Plaster of Paris – CaSO4.1/2H2O
Washing Soda – Na2CO3.10H2O
Baking Soda – NaHCO3
Reason (R) : is a mild non-corrosive basic salt.
Answer: (a)
Explanation : Sodium hydrogen carbonate is a mild base which can be used as an antacid.
Reason (R) : Methane gas combines with oxygen to produce carbon dioxide and water.
Answer: (c)
Explanation : Burning of natural gas is an exothermic process.
Reason (R) : The soil is the nearest and richest source of raw materials like Nitrogen, Phosphorus and other minerals for the plants.
Answer: (b)
Explanation : Nitrogen is a vital element as it is the major component of chlorophyll. It is a compound by which plants use sunlight to produce sugars from water and carbon dioxide by the process of photosynthesis. It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants wither and die.
Reason (R) : Distance travelled by sunlight in the atmosphere is lesser during sunrise and sunset as compared to noon.
Answer: (c)
Explanation : Sun appears reddish during sunrise or sunset because sunlight travels greater distance/path in atmosphere as compared to noon. So, high scattering of blue light takes place and red light reaches us.
Reason (R) : Hydrochloric acid creates an acidic medium to activate protein digesting enzymes.
Answer: (a)
Explanation : Walls of stomach releases hydrochloric acid which provide acidic medium for pepsin enzyme to act on proteins.
Answer: (c)
Explanation : Plant needs three things for photosynthesis that is carbon dioxide, water and sunlight. In this experiment plants are kept airtight with the presence of potassium hydroxide which absorbs all the carbon dioxide present in the jar. Step 3 is not an essential step of experiment, but we can place plants in open after experiment.
Answer: (b)
Explanation : A respiratory organ consists of a surface across which gaseous exchange by simple diffusion can occur between blood and either water or air.The surface must be moist enough to allow the cells to permit sufficient gas exchange and thin enough to permit rapid diffusion.
Answer: (c)
Explanation : In the experiment it is observed that exhaled air makes the lime water milky, indicating the presence of more carbon dioxide in the exhaled air.
Answer: (c)
Explanation : Power for converging/convex lens is positive.
P = = +5 D
Answer: (d)
Explanation : In case of concave mirror, virtual image is formed when object is placed between F and P.
Here, focal length (f) = = 15 cm
So, object should be placed between 0 cm (Pole) and 15 cm (focus).
Answer: (b)
Explanation: In herbivores like deer, length of small intestine is longer as compared to carnivores because of the food habit. Herbivores are plant eating animals and it has cellulose, which takes longer time to digest. Because of the relative difficulty with which various kinds of plant foods are broken down due to large amounts of indigestible fibers, herbivores have significantly longer gut than carnivores. The long intestine allows adequate time and space for absorption of the nutrients.
Answer: (b)
Explanation : Phloem is a complex permanent plant tissue. It is made up of sieve tubes, companion cells, phloem fibres and phloem parenchyma. It helps in the transportation of the food prepared by leaves to various plant parts. It can transport food in upward as well as downward direction. Both sieve tube and companion cells are two different types of cells that are found in the phloem of angiosperms. They help in transportation of food throughout the plant.
Answer: (d)
Explanation - Converging lens means convex lens
f = + 30 cm
Now, real image is always inverted
By lens formula:
Answer: (b)
Explanation : In case of concave mirror, if object is placed at center of curvature, image is formed real, inverted, same size and at center of curvature itself. So, option (b) is false.
Answer: (d)
Explanation : When ray travels from medium 1 to medium 2, it bends towards normal. This is the case of light travelling from rarer to denser medium, hence
n2 > n1. Again, ray bends towards normal while traveling from medium 2 to 3. Hence, n3 > n2
Answer: (d)
Explanation : As we know, Absolute refractive index of a medium is defined as the ratio of the velocity of light in vacuum to the velocity of light in the medium.
So,
Hence,
Similarly,
Answer: (c)
Explanation :
Answer: (c)
Explanation : From the above graph, it is clear that initial pH of water is 7 but when dilute acid is added it goes down or decreases rapidly due to increase in concentration of H+.
A student, took four metals P, Q, R and S and carried out different experiments to study the properties of metals. Some of the observations were:
Answer: (b)
Explanation : Metal like sodium Na (R) is highly reactive and it should be kept in kerosene oil so that it cannot come in the contact of air to avoid explosion.
Answer: (d)
Explanation : Magnesium metal (Q) after reacting with hot water starts floating.
Answer: (a)
Explanation : Metal like aluminium do not react with cold or hot water but reacts with steam.
Answer: (c)
Explanation - This is as per the reactivity series.
Case-II:
The figure shown below represents a common type of dialysis called as Haemodialysis. It removes waste products from the blood. Such RB excess salts, and urea which are insufficiently removed by the kidney in patients with kidney failure. During the procedure, the patient’s blood is cleaned by filtration through a series of semi-permeable membranes before being returned to the blood of the patient. On the basis of this, answer the following questions:
Answer: (c)
Explanation : The blood flows through small tubes inside the dialysis device. These are made of semipermeable membranes and are surrounded by dialysis fluid. The dialysis fluid flows in the opposite direction to the blood which is termed as counter-current flow. It helps in removal of harmful substances, waste products and excess water from the blood and gets rid of them together with the dialysis fluid.
Answer: (c)
Explanation: Artificial kidney or dialysis helps in the following ways:
1. It removes wastes, excessive salt and excess water from the body, preventing their build-up.
2. Dialysis also helps to control blood pressure.
Answer: (a)
Explanation : Artificial kidneys contain a number of tubes with a semi-permeable lining suspended in a tank filled with dialysing fluid. This fluid has the same osmotic pressure as blood, except that it is devoid of nitrogenous wastes. The patient’s blood is passed through these tubes. During this passage, the waste products from the blood pass into dialysing fluid by diffusion. The purified blood is pumped back into the patient.
Answer: (c)
Explanation : The major function of tubules is reabsorption and the process can either be through active transport or through passive transport. Also secretions by tubules help in the urine formation without affecting the electrolyte balance of the body.
Case-III: A compound microscope is an instrument which consists of two lenses L1 and L2. The lens L1 called objective, forms a real, inverted and magnified image of the given object. This serves as the object for the second lens L2; the eye piece The eye piece function like a simple microscope or magnifier. It produces the final image, which is inverted with respect to the original object, enlarged and virtual.
Answer: (b)
Explanation – As L1 is forming real image, it must be convex lens (as concave lens cannot form real image). Also as L2 forms magnified and virtual image, it must be convex lens too (as concave lens form virtual and diminished image).
Answer: (d)
Explanation : As L1 forms real and magnified image, value is more than 1 and sign is negative as image is inverted with respect to object.
Answer: (d)
Explanation : As L2 forms virtual and magnified image, value is more than 1 and sign is positive as image is erect with respect to first image (object for L2) formed by L1.
Answer: (b)
Explanation –