Tag: let's play with water

$14$ g of an element X combines with $16$ g of oxygen, then the element X could have an atomic weight of $7$ amu and its oxide is $X _2O $.
When the atomic weight is $7$, $14$ g will corresponds to $2$ moles.
$16$ g of oxygen corresponds to $1$ mole. 

$2KClO _3\rightarrow 2KCl+3O _2$
$2\times 122.5$ grams shows a wieght loss of  $3\times32 grams$
So 245 grams of $KClO _3$ is 100%
96 grams of $O _2$ is X%
$x=\frac{100\times 96}{245}=39.17$.
Hence option C is correct.

$Ag _2CO _3\rightarrow Ag _2O+CO _2(g)$
I mole of $Ag _2CO _3$ (275.74) grams  on decomposition gives a mass residue of 231.73 grams of $Ag _2O$ remaning mass is liberated as $CO _2$ gas.
If 1.38 grams $Ag _2CO _3$ is hetaed it produces X grams of mass residue of  $Ag _2O$
$X=\frac{1.38\times 231.739}{275.745}=1.16$ grams
Hence option A is correct.

$2H _2S+SO2\rightarrow 2H _2O+3S$

According to the equation $2\times 22.4 $ litre of  $H _2S$ gas reacts with $22.4$ litre of $SO _2$
So $5$ litre of $H _2S$ reacts with $10$ litre of $SO _2$
Hence option $A$ is correct.

The water vapor rises in the atmosphere due to heating of water by sunlight and there it cools down and forms tiny water droplets through something called condensation. When they all combine together, they grow bigger and are too heavy to stay up there in the air. This is when they will fall to the ground as rain, or maybe snow or hail by gravity.

The thermal resistance of heat transfer is low in drop wise condensation.

The evaporation takes place at all the time