If ${10}^{10}$ wheat grains are distributed each second, the time taken to distribute one Avogadro number of wheat grains would be -

$1. 1.91 \times {10}^6 \mathrm{years}$
$2. 2.31 \times {10}^4 \mathrm{years}$
$3. 3.84 \times {10}^{6 }\mathrm{years}$
$4. 1.91 \times {10}^5 \mathrm{years}$

A reading on Fahrenheit scale is $200°\mathrm{F}$. The same reading on celsius scale will be :
1. 40°C
2. 94°C
3. 93°C
4. 30°C

1. 1.5 M

2. 1.66 M

3. 0.017 M

4. 1.59 M

The mass percent of carbon in carbon dioxide is: 

The incorrect statement among the following is:

Which of the following statements is correct about the reaction is given below?

$4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{g}\right)$

Identify the reaction that does not obey the law of conservation of mass from the provided options:

1. $2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

2. ${\mathrm{C}}_3{\mathrm{H}}_8\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

3. ${\mathrm{P}}_4\left(\mathrm{s}\right)+5{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{P}}_4{\mathrm{O}}_{10}\left(\mathrm{s}\right)$

4. ${\mathrm{CH}}_4\left(\mathrm{g}\right)+2{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

Which of the following statement indicates that the law of multiple proportions is being followed?

Match the following:

Match the following physical quantities with units.

Codes: