3. Which oxidation-reduction reactions are best balanced by the half-reaction method? (1 point)

How many moles of C2H2 are needed to react completely with 84.0 mol O2?

Airida [17]

33.6 moles are needed to completely react with 84.0 moles of O2

3 0

3 years ago

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To find the molecular formula from the empirical formula, one must determine the compounds _____

xxTIMURxx [149]

Answer:

Relative molecular of the compound or infomation like vapour density, volume occupied by a known mass of its vapour at stp, etc

Explanation:

The molecular mass of a compound is twice its vapour density. We can find the molecular formula using the relationship below:

Empirical formula is the simplest formula of a compound. It repeats itself "n" times to become a molecular formula i.e (EF)ₙ = MF...... n is the number of times the empirical formula presents in a mole of the compound.
Most times, n is a whole number like 1,2,3,.....

7 0

3 years ago

Question 1

Alisiya [41]

It would be Xe because all of the other ones aren't filled up in the correct order which only happens during an excited state.

3 0

3 years ago

Considering that the mantle is 44.8% oxygen and 21.5% silicon by mass, calculate the mole ratio of oxygen atoms to silicon atoms

horrorfan [7]

The mantle has a mass of around $4.278 X 10 ^2^4 kg$ that is around 68.4% of earth's mass.

So to calculate moles we need to first find out the mass of oxygen and silicon present in mantle. It is given that oxygen is 44.8% by mass in mantle and 21.5% by mass in mantle, therefore to calculate its mass, we need to use $\text{mass percentage }=\frac{\text{mole of solute}}{\text{mass of solution}}\times100$

Now, to calculate mass percentage of oxygen

$44.8 =\frac{x}{4.278X10^2^4kg}\times100$

$x= 191.65\times10^2^2kg$

Similarly the mass of silicon can be calculated

$21.5 =\frac{x}{4.278X10^2^4kg}\times100$

$x=91.977\times10^2^2kg$

Now, the moles of any substance is calculated by

$\text{moles}= \frac{\text{given mass}}{\text{molar mass}}$

$\text{moles of oxygen}= \frac{191.65\times10^2^2kg}{2.6566962\times10^-^2^6kg}$

where, mass of oxygen in kilograms is $2.6566962\times10^-^2^6kg$

So, $\text{moles of oxygen}=72.1384\times10^4^8\text{moles of O}$

Similarly $\text{moles of silicon}= \frac{91.977\times10^2^2kg}{4.663\times10^-^2^6kg}$

$\text{moles of silicon}=19.724\times10^4^8\text{moles of Si}$

Now, to calculate mole ratio we need to divide every moles to the lowest calculated mole that is the moles of Si and round it off to the nearest whole number.

$\text{mole ratio of oxygen}= \frac{72.138\times10^4^8kg}{19.724\times10^4^8kg}$

$=3.65\approx 4$

$\text{mole ratio of Silicon}=\frac{19.724\times10^4^8}{19.724\times10^4^8}$

$=1$

$\text{Mole ratio of Oxygen : Mole ratio of Silicon} = 4:1$

6 0

4 years ago

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Two major discoveries of the gold foil experiment

tiny-mole [99]

Rutherford's gold foil experiment proved that there was a small, dense, positively charged nucleus at the center, which contained most of the mass of the atom. Which contained electrons orbiting the nucleus.

5 0

4 years ago