Question 1 :
The ratio of mass of nitrogen and oxygen in nitric oxide is in :
Question 2 :
A chemical equation is balanced in accordance with the law of
Question 3 :
Which of the following is true with respect to Law of Conservation of matter?
Question 4 :
When mass is enclosed in a system and none is allowed in or out, it's _____ will never change.
Question 5 :
A balanced chemical equation is in accordance with the law of conservation of masses___________.
Question 7 :
Which one of the following laws directly explains the law of conservation of mass?<br/>
Question 8 :
Which gas law relates the volume of a gas to the number of molecules of the gas?<br/>
Question 9 :
Find the total number of pennies in a tenth of a mole of pennies.
Question 10 :
A sample of ammonia has a mass of $51.1g$. How many molecules are in this sample?
Question 11 :
How many moles are present in $6.023\times 10^{22}$ molecules of $CO_2$?<br>
Question 12 :
What is the volume of $3.0\times {10}^{20}$ molecules of $HCl (g)$?
Question 13 :
The critical volume of a gas is 0.036 $lit. mol^{-1}$. The radius of the molecule will be (in cm):<br/>(Avogadro Number = $6 \times 10^{23}$)<br/>
Question 14 :
Law of definite proportion does not apply to nitrogen oxide because:
Question 15 :
If the ratio of the atoms by mass is altered then :
Question 17 :
In a compound the ratio of the atoms or element by mass remains always same irrespective of :<br/>
Question 18 :
Different samples of water were found to contain hydrogen and oxygen in the ratio of 1 : 8. This shows the law of:<br/>
Question 19 :
The ratio of mass of nitrogen and oxygen in nitric oxide is in :
Question 20 :
The % of Copper and Oxygen in samples of CuO obtained by different methods were found to be the same. This proves the law of:<br/>
Question 21 :
Assertion: Matter can neither be created nor destroyed.
Reason: This is law of definite proportions.
Question 23 :
14 g of element X combine with 16 g of oxygen. On the basis of this information, which of the following is a correct statement?
Question 24 :
The volume of ${ H }_{ 2 }S$ gas measured at $1$ atm and ${ 0 }^{ o }C$ produced when $16.6\ g$ of $KI$ reacts with excess of ${ H }_{ 2 }{ SO }_{ 4 }$, is:
Question 25 :
Assertion: In the following reaction, <br>$SO_2 + 2H_2S\longrightarrow 3S + 2H_2O$<br>$1$ mole $SO_2$ and $1$ mole $H_2S$ forms $3$ moles sulphur.
Reason: $1$ mole $SO_2$ and $2$ mole $H_2S$ form $3$ moles sulphur and $2$ moles $H_2O$.
Question 26 :
Which choice shows the answer to the following mathematical operation with the correct number of significant figures?<br/>$2.8\times 8.96 = ? $
Question 28 :
Number of water molecules in one litre of pure water is :
Question 29 :
A sample was weighted using two different balances. The result's were (i) $3.929g$ (ii) $4.0g$. How would the weight of the sample be reported?
Question 32 :
If the true value for a result is 4.00 cm and a student takes two measurements and reports the result as 3.94 cm and 3.95 cm, then these values are:
Question 33 :
Assertion: Pure water obtained from different sources such as river, well, spring, sea etc. always contain hydrogen and oxygen combined in the ratio $1 : 8$ by mass.
Reason: A chemical compound always contains elements combined together in same proportion by mass, it was discovered by French chemist, Joseph Proust (1799).
Question 34 :
Potassium combines with two isotopes of chlorine $(^{35} Cl\,\, and\,\, ^{37}Cl)$ respectively to form two samples of $KCl$ Their formation follows the law of:
Question 35 :
10.0 g of CaCO$_3$ on heating gave 4.4 g of CO$_2$ and 5.6 g of CaO. The observation is in agreement with the:
Question 36 :
Cations absorb $6.023\times 10^{22}$ electrons for their reduction. How many equivalents of the ion are reduced?
Question 38 :
The percentage of copper and oxygen in samples of $CuO$ obtained by different methods were found to be the same. This illustrates the law of
Question 39 :
What is the final significant digit in the measurement of $16.280g$?
Question 41 :
$10$ mL of hydrogen combines with $5$ mL of oxygen to yield water. When $200$ mL of hydrogen at STP is passed over heated $CuO$, the $CuO$ loses $0.144$ g of its weight. State the law illustrated by these chemical combinations.
Question 42 :
Calculate the volume of $CO_{2}$ evolved by the combustion of $50$ ml of a mixture containing $40$ per $C_{2}H_{4}$ and $60$ per $CH_{4}$ (by volume).
Question 43 :
Zinc sulphate contains $22.65$% $Zn$ and $43.9$% ${H}_{2}O$. If the law of constant proportions is true, then the mass of zinc required to give $40g$ crystal will be:
Question 44 :
At NTP, 10 litre of hydrogen sulphide gas reacted with 10 litre of sulphur dioxide gas. The volume of gas, after the reaction is complete, would be:
Question 45 :
Assertion: Carbon monoxide is considered a compound but carbon and oxygen as elements.
Reason: A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus. While the compound is composed of two or more separate elements.
Question 46 :
The mass of oxygen with which 13.5 g of aluminium will completely react is:
Question 47 :
10 ml of a mixture of $CH_{4}, C_{2}H_{4}$ and $CO_{2}$ were exploded with excess of air. After explosion, there was contraction on cooling of 17 ml and after treatment with KOH, there was further reduction of 14 ml. What is the composition of the mixture?
Question 48 :
$1.375$ g of cupric oxide was reduced by heating in a current of hydrogen and the weight of copper obtained was $1.098$ g. In another experiment, $1.179$ g of copper was dissolved in nitric acid and the resulting solution was evaporated to dryness. The residue of copper nitrate when strongly heated was converted into $1.4476$ g of cupric oxide. The result of this process show :
Question 49 :
In a gaseous reaction of the type, $aA + bB \rightarrow  cC + dD$, which is wrong?<br/>
Question 50 :
20 ml of a mixture of $C_{2}H_{2}$ and CO was exploded with 30ml of oxygen. The gases after the reaction had a volume of 34ml. On treatement with $KOH$, 8ml of oxygen remained. Calculate the composition of the mixture.
