Select all that apply:

a)the mass ratio of oxygen to carbon in co is twice the mass ratio of oxygen to carbon in co2.
b)the mass ratio of oxygen to carbon in co is 1.33 for every sample of co.
c)mass ratio of oxygen to carbon in co2 is 2.667 for every sample of co2.
d)for two compounds of c and o, the mass ratio of c to o in one compound is a multiple of the mass ratio of c to o in the other compound.

Option B, C and D are correct.

Carbon is a non metallic element with the atomic number 6 and mass number 12. Whereas oxygen is also a non metallic element with the atomic number 8 and mass number of 16.

In carbon monoxide, the mass ratio of oxygen to carbon is 16:12 =1.33. This ratio is same for every sample of carbon monoxide, because carbon monoxide has the universal formula of CO.

Similarly In carbon dioxide , the mass ratio of oxygen to carbon is 32:12 =2.667. This ratio is same for every sample of carbon dioxide, because carbon dioxide has the universal formula of .

Even we can see that the mass ratio of oxygen to carbon in carbon dioxide is just twice the mass ratio of oxygen to carbon in carbon monoxide, because of presence of twice as much as oxygen per molecule of carbon dioxide than carbon monoxide.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.