Question 1 :
The energy released (exothermic) or adsorbed (endothermic) in a chemical reaction is a result of:<br/>
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 :
The actual product of 4.327 and 2.8 is 12.1156. The correctly reported answer will be :<br/>
Question 22 :
If 'M' is the molecular weight of a gas, what volume in $l$ at STP would be occupied by M/4 g of that gas?
Question 23 :
Assertion: The law of conversation of mass apply to the burning a candle.
Reason: During the burning of candle, the wax is converted into smoke, gas, soot and melted wax.The mass of these products is same as the melted wax.
Question 24 :
REACTANT(S)                           PRODUCT(S)<br/>Magnesium + Oxygen $\longrightarrow$     Magnesium Oxide + Oxygen<br/> 48.6 g        +     50.0 g $\longrightarrow$     80.6 g                   +      ? <br/><br/>Predict the mass of oxygen that will be left over after the reaction of 48.6 grams of magnesium with 50.0 grams of oxygen. <br/>
Question 25 :
The correctly reported answer of the addition of 4.523, 2.3 and 6.24 will have significant figures:<br/>
Question 26 :
What volume of hydrogen at NTP will be liberated when 3.25 g of zinc completely dissolve in dilute HCl? <br/>[At. mass of Zn = 65]<br/>
Question 27 :
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 28 :
A student performs a titration with different burettes and finds titre values of $25.2$ ml, $25.25$ ml and $25.0$ ml. The number of significant figures in the average titre value is :
Question 29 :
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.
Question 30 :
Assertion: STATEMENT 1: $SO_{2}$ obtained either by the oxidation of $H_{2}S$ or decomposition of sulphate salt contains sulphur and oxygen in the mass ratio $1 : 2.$
Reason: STATEMENT 2: $S_{(s)}+O_{2(g)}\rightarrow SO_{2(g).}$
