Question 2 :
What is meant by the half a water molecule in the formula of plaster of paris?
Question 3 :
Which of the following is not one of the reactants to produce baking soda?
Question 4 :
Complete the following reaction: Metal carbonate/Metal hydrogen carbonate + ______ $\rightarrow$ Salt + ______ +water.
Question 5 :
The following reaction is an example of :
$Fe_{2}O_{3} + 2Al \rightarrow Al_{2}O_{3} + 2Fe$
Question 6 :
Write the balanced chemical equations for the following reactions:
Barium chloride + Potassium sulphate $\rightarrow$ Barium sulphate + Potassium chloride
Question 7 :
Translate the following statements into chemical equations and then balance them:
Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
Question 8 :
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Question 9 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d27273b230584979bae.JPG' />
In the given figure, name the carbon compound.
Question 11 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d25273b230584979bac.JPG' />
In the given figure, name the carbon compound.
Question 14 :
The kidneys in human beings are a part of the system for
Question 16 :
What criteria do we use to decide whether something is alive ?
Question 17 :
In the following cross, RR YY x rr yy, the characteristics of the progeny is
Question 19 :
Select the statement that describe characteristics of genes :
(i) Genes are specific sequence of bases in a DNA molecule
(ii) A gene does not code for proteins
(iii) In individuals of a given species, a specific gene is located on a particular chromosome
(iv) Each chromosome has only one gene
Question 20 :
In human beings, the statistical probability of getting either a male or a female child is
Question 24 :
The most important safety method used for protecting home appliances from short circuiting or overloading is
Question 25 :
Resistance of a metal wire of length 1 m is 26 Ω at 20°C. If the diameter of the wire is 0.3 mm, what will be the resistivity of the metal at that temperature?
Question 26 :
An electric motor takes 5 A from a 220 V line. What is the power of the motor?
Question 27 :
How much power is used in 2$\Omega$ resistor when a 6 V battery is connected in series with 1$\Omega$ and 2$\Omega$ resistors?
Question 28 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d35273b230584979bbf.PNG' />
Above image is the symbol of ______ in circuit diagram.
Question 30 :
Food cans are coated with tin and not with zinc because
Question 31 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19c7e273b230584979aeb.JPG' />
Samples of four metals A, B, C and D were taken and added to the different solution one by one. The results obtained have been tabulated above. Use the given table to answer the following questions about metals A, B, C and D.
Arrange the metals in decreasing order of reactivity.
Question 32 :
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Question 33 :
What will be the action of the Carbonated soft drink on litmus paper?
Question 36 :
Fill in the blank: Magnesium nitrate ($Mg(NO_3)_2$) is formed using ________(base) and $HNO_3$(acid)
Question 37 :
Balance the chemical equation:- $HNO_3 + Ca (OH)_2 → Ca (NO_3)_2 + H_2O$.
Question 39 :
What is the balanced chemical equation for Zinc carbonate(s) → Zinc oxide (s) + Carbon dioxide (g) ?
Question 41 :
Use Mendeleev's periodic table to predict the formulae for the oxides of the elements 'Si'.
Question 42 :
Use Mendeleev's periodic table to predict the formulae for the oxides of the elements 'Al'.
Question 43 :
Use Mendeleev's periodic table to predict the formulae for the oxides of the elements 'C'.
Question 44 :
Name two elements that have two electrons in their outermost shells.
Question 49 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19cb9273b230584979b30.JPG' />
In the above diagram of a compound, which all functional groups are present:
Question 50 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19c93273b230584979b04.JPG' />
State True or False: The above figure is a structural isomer of butane.
Question 51 :
A compound C (molecular formula, $C_2H_4O_2$) reacts with Na - metal to form a compound R and evolves a gas which burns with a pop sound. Compound C on treatment with an alcohol A in presence of an acid forms a sweet smelling compound S (molecular formula, $C_3H_6O_2$). On addition of NaOH to C, it also gives R and water. S on treatment with NaOH solution gives back R and A. Identify S.
Question 52 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19cba273b230584979b32.JPG' />
Write the name of the above functional group.
Question 53 :
In human males, the testes lie in the scrotum, because it helps in the
Question 54 :
State whether the statement is TRUE or FALSE : Colonies of yeast fail to multiply in water, but multiply in sugar solution.
Question 55 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61cc185078c526e972caea1f.PNG' />
In the above figure, which part mention the function Production of egg
Question 56 :
In human females, an event that reflects onset of reproductive phase is
Question 57 :
A positively charged particle projected towards West is deflected towards North by a Magnetic Field. The direction of Magnetic Field is
Question 58 :
A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is pushed into the coil?
Question 59 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19cf4273b230584979b74.JPG ' />
In the above figure, a uniform magnetic field exists in the plane of paper pointing from left to right. In the field an electron and a proton move as shown . The electron and the proton experience
Question 60 :
A positively charged particle (alpha particle) projected towards West is deflected towards North by a magnetic field. The direction of magnetic field is:
Question 65 :
What type of image will form by a concave mirror, when an object is placed at centre of curvature of the mirror.
Question 66 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19cee273b230584979b6d.PNG' />
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61cc185478c526e972caea2b.PNG' />
In the above images, the first image is the ray of light incident on a convex lens and the second image is the complete path of the ray. Is the second image correct depiction of the path?
Question 67 :
Sudha finds out that the sharp image of the window pane of her science laboratory is formed at a distance of 15 cm from the lens. She now tries to focus the building visible to her outside the window instead of the window pane without disturbing the lens. What is the approximate focal length of this lens?
Question 68 :
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is :
Question 69 :
Among the statements given below select the ones that correctly describe the concept of sustainable development -
(i) Planned growth with minimum damage to the environment
(ii)Growth irrespective of the extent of damage caused to the environment
(iii)Stopping all developmental work to conserve the environment
(iv)Growth that is acceptable to all the stakeholders
Question 70 :
The pH of water sample collected from a river was found to be acidic in the range of 3.5 - 4.5, on the banks of the river where several factories that were discharging effluents into the river. The effluents of which one of the following factories is the most likely cause for lowering the pH of river water?
Question 71 :
Pick the right combination of terms which has no fossil fuel.
Question 72 :
The pH range most conducive for life of fresh water plants and animals is
Question 73 :
Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?
Question 74 :
A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. What is X?
Question 76 :
State True or False: Plants convert solar energy into chemical energy
