16 g of oxygen has the same number
Question: 16 g of oxygen has the same number of molecules as in (i) 16 g of CO (ii) 28 g of N2 (iii) 14 g of N2 (iv) 1.0 g of H2 Solution: Option (iii)14 g of N2and (iv)1.0 g of H2 are the answers....
Read More →Find the point on the curve
Question: Find the point on the curve $x^{2}+y^{2}-2 x-3=0$ at which the tangents are parallel to the $y$ - axis. Solution: Since, the tangent is parallel to $y$-axis, its slope is not defined, then the normal is parallel to $x$ - axis whose slope is zero. $\mathrm{i} . e, \frac{-1}{\frac{\mathrm{d} y}{\mathrm{dx}}}=0$ $\Rightarrow \frac{-1}{\frac{1-x}{y}}=0$ $\Rightarrow \frac{-y}{1-x}=0$ $\Rightarrow y=0$ Substituting $y=0$ in $x^{2}+y^{2}-2 x-3=0$ $\Rightarrow x^{2}+0^{2}-2 x x-3=0$ $\Rightar...
Read More →Which of the following solutions have
Question: Which of the following solutions have the same concentration? (i) 20 g of NaOH in 200 mL of solution (ii) 0.5 mol of KCl in 200 mL of solution (iii) 40 g of NaOH in 100 mL of solution (iv) 20 g of KOH in 200 mL of solution Solution: Option (i)20 g of NaOH in 200 mL of solution and (ii)0.5 mol of KCl in 200 mL of solutionare the answers....
Read More →Find the point on the curve
Question: Find the point on the curve $x^{2}+y^{2}-2 x-3=0$ at which the tangents are parallel to the $y$ - axis. Solution: Since, the tangent is parallel to $y$-axis, its slope is not defined, then the normal is parallel to $x$ - axis whose slope is zero. $\mathrm{i} . e, \frac{-1}{\frac{\mathrm{d} y}{\mathrm{dx}}}=0$ $\Rightarrow \frac{-1}{\frac{1-x}{y}}=0$ $\Rightarrow \frac{-y}{1-x}=0$ $\Rightarrow y=0$ Substituting $y=0$ in $x^{2}+y^{2}-2 x-3=0$ $\Rightarrow x^{2}+0^{2}-2 x x-3=0$ $\Rightar...
Read More →Which of the following pairs have
Question: Which of the following pairs have the same number of atoms? (i) 16 g of O2(g) and 4 g of H2(g) (ii) 16 g of O2and 44 g of CO2 (iii) 28 g of N2and 32 g of O2 (iv) 12 g of C(s) and 23 g of Na(s) Solution: Option (iii)28 g of N2and 32 g of O2 and (iv)12 g of C(s) and 23 g of Na(s)are the answers....
Read More →Find the point on the curve
Question: Find the point on the curve $x^{2}+y^{2}-2 x-3=0$ at which the tangents are parallel to the $y$ - axis. Solution: Since, the tangent is parallel to $y$-axis, its slope is not defined, then the normal is parallel to $x$ - axis whose slope is zero. $\mathrm{i} . e, \frac{-1}{\frac{\mathrm{d} y}{\mathrm{dx}}}=0$ $\Rightarrow \frac{-1}{\frac{1-x}{y}}=0$ $\Rightarrow \frac{-y}{1-x}=0$ $\Rightarrow y=0$ Substituting $y=0$ in $x^{2}+y^{2}-2 x-3=0$ $\Rightarrow x^{2}+0^{2}-2 x x-3=0$ $\Rightar...
Read More →Sulphuric acid reacts with sodium hydroxide as follows:
Question: Sulphuric acid reacts with sodium hydroxide as follows: H2SO4+ 2NaOH Na2SO4+ 2H2O When 1L of 0.1M sulphuric acid solution is allowed to react with 1L of 0.1M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained is (i) 0.1 mol L-1 (ii) 7.10 g (iii) 0.025 mol L-1 (iv) 3.55 g Solution: Option (ii)7.10 g and (iii)0.025 mol L-1are the answers....
Read More →One mole of oxygen gas at STP is equal to _______.
Question: One mole of oxygen gas at STP is equal to _______. (i) 6.022 1023molecules of oxygen (ii) 6.022 1023atoms of oxygen (iii) 16 g of oxygen (iv) 32 g of oxygen Solution: Option (i)6.022 1023 molecules of oxygen and (iv)32 g of oxygen are the answers....
Read More →Find the point on the curve
Question: Find the point on the curve $x^{2}+y^{2}-2 x-3=0$ at which the tangents are parallel to the $x$ - axis Solution: Given: The curve is $x^{2}+y^{2}-2 x-3=0$ Differentiating the above w.r.t $x$, we get The Slope of tangent, $\Rightarrow 2 x^{2}-1+2 y^{2}-1 \frac{d y}{d x}-2-0=0$ $\Rightarrow 2 x+2 y \frac{d y}{d x}-2=0$ $\Rightarrow 2 y \frac{d y}{d x}=2-2 x$ $\Rightarrow \frac{d y}{d x}=\frac{2-2 x}{2 y}$ $\Rightarrow \frac{d y}{d x}=\frac{1-x}{y} \ldots(1)$ (i) Since, the tangent is par...
Read More →Find the general solution of each of the following equations:
Question: Find the general solution of each of the following equations: (i) $\sin 2 x=\frac{1}{2}$ (ii) $\cos 3 \mathrm{x}=\frac{1}{\sqrt{2}}$ (iii) $\tan \frac{2 \mathrm{x}}{3}=\sqrt{3}$ Solution: To Find: General solution. (i) Given: $\sin 2 x=\frac{1}{2}$ Formula used: $\sin \theta=\sin \alpha \Rightarrow \theta=n \pi+(-1)^{n} \alpha, n \in I$ By using above formula, we have $\sin 2 x=\frac{1}{2}=\sin \frac{\pi}{6} \Longrightarrow 2 x=n \pi+(-1)^{n} \cdot \frac{\pi}{6} \Longrightarrow x=\frac...
Read More →Which of the following statements indicates
Question: Which of the following statements indicates that the law of multiple proportions is being followed. (i) Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio 1:2. (ii) Carbon forms two oxides namely CO2 and CO, where masses of oxygen which combine with a fixed mass of carbon are in the simple ratio 2:1. (iii) When magnesium burns in oxygen, the amount of magnesium taken for the reaction is equal to the amount of magnesium in magnesium oxide form...
Read More →Which of the following reactions is not correct
Question: Which of the following reactions is not correct according to the law of conservation of mass. (i) 2Mg(s) + O2(g) 2MgO(s) (ii) C3H8(g) + O2(g) CO2(g) + H2O(g) (iii) P4(s) + 5O2(g) P4O10(s) (iv) CH4(g) + 2O2(g) CO2(g) + 2H2O (g) Solution: Option (ii)C3H8(g) + O2(g) CO2(g) + H2O(g) is the answer....
Read More →Which of the following statements is correct
Question: Which of the following statements is correct about the reaction given below: 4Fe(s) + 3O2(g) 2Fe2O3(g) (i) The total mass of iron and oxygen in reactants = total mass of iron and oxygen in product therefore it follows the law of conservation of mass. (ii) The total mass of reactants = total mass of product; therefore, the law of multiple proportions is followed. (iii) Amount of Fe2O3 can be increased by taking any one of the reactants (iron or oxygen) in excess. (iv) Amount of Fe2O3 pr...
Read More →Find the point on the curve
Question: Find the point on the curve $\frac{x^{2}}{4}+\frac{y^{2}}{25}=1$ at which the tangents are parallel to the $y$ - axis. Solution: Since, the tangent is parallel to $y$ - axis, its The Slope is not defined, then the normal is parallel to $x$-axis whose The Slope is zero. i.e, $\frac{-1}{\frac{d y}{d x}}=0$ $\Rightarrow \frac{-1}{\frac{-25 x}{4 y}}=0$ $\Rightarrow \frac{-4 y}{25 x}=0$ $\Rightarrow y=0$ Substituting $y=0$ in $\frac{x^{2}}{4}+\frac{y^{2}}{25}=1$, $\Rightarrow \frac{x^{2}}{4...
Read More →Which of the following statements about
Question: Which of the following statements about a compound is incorrect? (i) A molecule of a compound has atoms of different elements. (ii) A compound cannot be separated into its constituent elements by physical methods of separation. (iii) A compound retains the physical properties of its constituent elements. (iv) The ratio of atoms of different elements in a compound is fixed. Solution: Option (iii)A compound retains the physical properties of its constituent elements is the answer....
Read More →If the density of a solution
Question: If the density of a solution is 3.12 g mL-1, the mass of 1.5 mL solution in significant figures is _______. (i) 4.7g (ii) 4680 10 -3g (iii) 4.680g (iv) 46.80g Solution: Option (i)4.7gis the answer...
Read More →The empirical formula and molecular mass
Question: The empirical formula and molecular mass of a compound are CH2O and 180 g respectively. What will be the molecular formula of the compound? (i) C9H18O9 (ii) CH2O (iii) C6H12O6 (iv) C2H4O2 Solution: Option (iii)C6H12O6is the answer....
Read More →Find the point on the curve
Question: Find the point on the curve $\frac{x^{2}}{4}+\frac{y^{2}}{25}=1$ at which the tangents are parallel to the Solution: $x$ - axis Given: The curve is $\frac{x^{2}}{4}+\frac{y^{2}}{25}=1$ Differentiating the above w.r.t $x$, we get the The Slope of a tangent, $\Rightarrow \frac{2 x^{2-1}}{4}+\frac{2 y^{2-1} \times \frac{d y}{d x}}{25}=0$ Cross multiplying we get, $\Rightarrow \frac{25 \times 2 \mathrm{x}+4 \times 2 \mathrm{y} \times \frac{\mathrm{dy}}{\mathrm{ds}}}{100}=0$ $\Rightarrow 50...
Read More →Find the general solution of each of the following equations:
Question: Find the general solution of each of the following equations: (i) $\cos x=\frac{-1}{2}$ (ii) $\operatorname{cosec} x=-\sqrt{2}$ (iii) $\tan x=-1$ Solution: To Find: General solution. Formula used: $\cos \theta=\cos \alpha \Rightarrow \theta=2 \mathrm{n} \pi \pm \alpha, \mathrm{n} \in I$ By using above formula, we have $\cos x=\frac{-1}{2}=-\cos \left(\frac{\pi}{3}\right)=\cos \left(\pi-\frac{\pi}{3}\right)=\cos \left(\frac{2 \pi}{3}\right) \Rightarrow x=2 n \pi \pm \frac{2 \pi}{3}, n \...
Read More →What is the mass per cent of carbon
Question: What is the mass per cent of carbon in carbon dioxide? (i) 0.034% (ii) 27.27% (iii) 3.4% (iv) 28.7% Solution: Option(ii) 27.27%is the answer....
Read More →One mole of any substance contains
Question: One mole of any substance contains 6.022 1023atoms/molecules. Number of molecules of H2SO4present in 100 mL of 0.02M H2SO4solution is ______. (i) 12.044 1020molecules (ii) 6.022 1023molecules (iii) 1 1023molecules (iv) 12.044 1023molecules Solution: Option(i) 12.044 1020 moleculesis the answer....
Read More →What will be the molality
Question: What will be the molality of the solution containing 18.25 g of HCl gas in 500 g of water? (i) 0.1 m (ii) 1 M (iii) 0.5 m (iv) 1 m Solution: Option (iv) is the answer....
Read More →At what points on the curve
Question: At what points on the curve $y=x^{2}-4 x+5$ is the tangent perpendicular to the line $2 y+x=7 ?$ Solution: Given: The curve $y=x^{2}-4 x+5$ and line is $2 y+x=7$ $y=x^{2}-4 x+5$ Differentiating the above w.r.t $x$, we get the Slope of the tangent, $\Rightarrow \frac{d y}{d x}=2 x^{2}-1-4+0$ $\Rightarrow \frac{d y}{d x}=2 x-4 \ldots(1)$ Since, line is $2 y+x=7$ $\Rightarrow 2 y=-x+7$ $\Rightarrow y=\frac{-x+7}{2}$ $\Rightarrow y=\frac{-x}{2}+\frac{7}{2}$ $\therefore$ The equation of a s...
Read More →If the concentration of glucose
Question: If the concentration of glucose (C6H12O6) in the blood is 0.9 g L-1, what will be the molarity of glucose in the blood? (i) 5 M (ii) 50 M (iii) 0.005 M (iv) 0.5 M Solution: Option (iii) is the answer....
Read More →The number of atoms present in one mole
Question: The number of atoms present in one mole of an element is equal to Avogadro number. Which of the following element contains the greatest number of atoms? (i) 4g He (ii) 46g Na (iii) 0.40g Ca (iv) 12g He Solution: Option (iv) is the answer....
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