Methane and ethane are both made up of carbon and hydrogen. in methane, there are 12.0g of carbon for every 4.00g of hydrogen, a ratio of 3: 1 by mass. in ethane, there are 24.0g of carbon for every 6.00g of hydrogen, a ratio of 4: 1 by mass. this is a statement of the law of
answer a. conservation of matter
b. multiple proportions
c. octaves
d. conservation of mass
e. constant composition

Option b. multiple proportions

Explanation:

Let's do some discarting options first:

Conservation of matter involves that the matter that we have at the beggining of a reaction will conver at the end of reaction. In this case, we do not have a reaction involved, therefore, this option can be discarted.

Conservation of mass involves that the total mass of the reactants will be equal to the total mass of the products of reaction. Once again, we do not have a reaction here, so this option can be discarted as well.

Constant composition, means that the composition of a mass will remain constant in every moment and in every compound involved. In this case, methane (CH4) and Ethane (C2H6), we do not have the same composition of mass, so this option is discarted.

Now, multiple proportions states that when two elements combine to form one or more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. In this case, we are combining C and H, and depending of their weights, they are combining and giving different products because of the ratio of it's element in moles. Therefore, this is a great example of Multiple proportions, and thus, the correct answer.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.