B, turns red litmus paper to blue
Answer:
4Fe + 3O₂ → 2Fe₂O₃
General Formulas and Concepts:
<u>Chemistry - Reactions</u>
Explanation:
<u>Step 1: Define</u>
RxN: Fe + O₂ → Fe₂O₃
<u>Step 2: Balance</u>
We need to balance both Fe and O.
LCM of 2 and 3 is 6:
Fe + 3O₂ → 2Fe₂O₃
We now need the same amount of Fe on both sides:
4Fe + 3O₂ → 2Fe₂O₃
Word equation - calcium + oxygen -> calcium oxide
Chemical equation - Ca + O2 -> CaO2
Hope this helps!
Answer:
The molar mass of the unknown gas is 
Explanation:
Let assume that the gas is O2 gas
O2 gas is to effuse through a porous barrier in time t₁ = 4.98 minutes.
Under the same conditions;
the same number of moles of an unknown gas requires time t₂ = 6.34 minutes to effuse through the same barrier.
From Graham's Law of Diffusion;
Graham's Law of Diffusion states that, at a constant temperature and pressure; the rate of diffusion of a gas is inversely proportional to the square root of its density.
i.e

where K = constant
If we compare the rate o diffusion of two gases;

Since the density of a gas d is proportional to its relative molecular mass M. Then;

Rate is the reciprocal of time ; i.e

Thus; replacing the value of R into the above previous equation;we have:

We can equally say:





