How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)
4.1g
6.1g
8.1g
16.2g
Correct answer is C
2HBr + C3H4 \(\to\) C3H6 + 2Br
162gms of HBr reacts with 40gms of propyne 2gms of propyne will react with
\(\frac{162}{40} \times \frac{2}{1}\) = 8.1gms HBr
50 cm3
10 cm3
40 cm3
30 cm3
70 cm3
Correct answer is A
The equation of the reaction is:
\(2H_{{2}{(g)}} + O_{{2}{(g)}} = 2H_{2}O_{(g)}\)
Before Sparking we have : \(50cm^{3} : 20cm^{3}\)
On Sparking, \(40cm^{3} : 20cm^{3} : 40cm^{3}\)
After Sparking, we have \(10cm^{3} : 0 : 40cm^{3}\)
Hence, the volume of residual gases = \((10+40)cm^{3} = 50cm^{3}\)
Helium atoms are chemically unreactive because
there are no electrons around the nucleus
the number of protons equals the number of electrons
there are equal number of protons and neutrons in the nucleus
the outer electron shell is completely filled
the atoms contain only protons
Correct answer is D
No explanation has been provided for this answer.
Which of the following contains two amphoteric oxides?
sodium oxide, Zinc oxide , Magnesium oxide
Aluminium oxide, Calcium oxide, Zinc oxide
Potassium oxide, Lithium oxide, Carbon monoxide
Silver oxide, Lead oxide, Sodium oxide
Sulphur dioxide, Aluminium oxide, Carbon monoxide
Correct answer is B
No explanation has been provided for this answer.
Which of the following statements is true? When the potassium atom forms its ion
it gains one electron and becomes neutral
its atomic number decreases
it achieves electronic configuration of orgon
it loses one proton
it loses one neutron
Correct answer is C
No explanation has been provided for this answer.