Importance & Scope Of Chemistry - NEET Class 11 Free MCQ Test with solutions

• Cisplatin is particularly effective against testicular cancer.
• Taxol (paclitaxel) is a mitotic inhibitor used in cancer chemotherapy.
• AZT is used for helping AIDS victims.

Additional Information: Its mode of action has been linked to its ability to crosslink with the purine bases on the DNA; interfering with DNA repair mechanisms, causing DNA damage, and subsequently inducing apoptosis in cancer cells. 

• A molecule is made up of atoms bonded together. 
• The law of definite proportions, sometimes called Proust's law, or the law of constant composition states that a given chemical compound always contains its component elements in a fixed ratio (by mass) and does not depend on its source and method of preparation.

Since both statements A and B are correct, the correct option is D. 

The correct answer is Option A - 14 g

Use Ca = 40 g mol^-1, O = 16 g mol^-1, so O₂ = 32 g mol^-1 and CaO = 56 g mol^-1.

Moles of calcium = 10 g ÷ 40 g mol^-1 = 0.25 mol.

Moles of oxygen (as O₂) = 10 g ÷ 32 g mol^-1 = 0.3125 mol.

The reaction consumes 2 mol Ca per 1 mol O₂, so oxygen required for 0.25 mol Ca is 0.125 mol; available oxygen is greater, therefore calcium is the limiting reagent.

Moles of CaO formed = moles of limiting reagent Ca = 0.25 mol.

Mass of CaO = 0.25 mol × 56 g mol^-1 = 14 g, which confirms the selected option.

• The significant figures of numbers are digits to convey the meaning that contributes to its measurement resolution.
• Non-zero digits are always significant.
• Here, 3256, this number has four non-zero numbers.
• That's why it has four significant figures.

Assume 100 g compound:

C = 40 g → 40/12 = 3.33 mol
H = 6.67 g → 6.67/1 = 6.67 mol
O = 53.33 g → 53.33/16 = 3.33 mol

Divide by smallest (3.33):

C = 1
H = 2
O = 1

Empirical formula = CH₂O

The correct answer is Option B - 33.6%

2 NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

M(NaHCO₃) = 84 g mol^-1 and M(CO₂) = 44 g mol^-1.

From the equation, 2 mol NaHCO₃ (168 g) produce 1 mol CO₂ (44 g).

Therefore, 1 g of NaHCO₃ yields 44/168 g of CO₂, and the mass of NaHCO₃ that produced the observed CO₂ is (168/44) × 0.44 = 1.68 g.

The percentage of NaHCO₃ in the mixture is (1.68/5) × 100 = 33.6%, which corresponds to the stated option.

• Precision indicates how closely repeated measurements match each other.
• Accuracy indicates how closely a measurement matches the correct or expected value.

Since the readings closely match the result and the expected value, the correct answer is that the values are both accurate and precise. 

Move the decimal point to the right of 0.00016 up to 4  places.

The decimal point was moved 7 places to the right to form the number 1.6

Since the numbers are less than 10 and the decimal is moved to the right, so we use a negative exponent here.

⇒ 0.00016 = 1.6 × 10^-4

Explanation: 

• Scientific notation is a form of presenting very large numbers or very small numbers in a simpler form.
• Scientific notation is used to represent the numbers that are very huge or very tiny in a form of multiplication of a single-digit number and 10 raised to the power of the respective exponent.
• The exponent is positive if the number is very large and it is negative if the number is very small. 

Let atomic weight of element X is x and that of element Y is y.

Molecular mass: The sum of the atomic masses of all the atoms in a molecule of a substance is called the molecular mass of the molecule.

Generally, we use relative atomic masses of atoms for calculating the molecular mass of 1 mole of any molecular or ionic substances.

The molecular formula of glucose is C₆H₁₂O₆

• The atomic mass of H = 1
• The atomic mass of C = 12
• The atomic mass of O = 16

Molecular mass of C₆H₁₂O₆ = 12 (Atomic mass of Hydrogen) + 6(Atomic mass of carbon) + 6(Atomic mass of oxygen)

= 12 × 1 + 6 × 12 + 6 × 16

= 12 + 72 + 96 = 180 u.