The answer is (b). As, vanadium is attached to five fluoride atoms, each flouride containing -1 oxidation state, hence five fluoride contains -5, to neutralize, vanadium should have +5 oxidation state.
Answer:
Y = 92.5 %
Explanation:
Hello there!
In this case, since the reaction between lead (II) nitrate and potassium bromide is:

Exhibits a 1:2 mole ratio of the former to the later, we can calculate the moles of lead (II) bromide product to figure out the limiting reactant:

Thus, the limiting reactant is the KBr as it yields the fewest moles of PbBr2 product. Afterwards, we calculate the mass of product by using its molar mass:

And the resulting percent yield:

Regards!
Given :
If I inhale 2.2 liters of gas at a temperature of 180 C and it heats to a temperature of 380 C in my lungs.
To Find :
The new volume of the gas.
Solution :
Since, their is no information about pressure, so we will assume that pressure is constant.
We know, relation between temperature and volume in constant pressure is :

Putting all given values in above equation, we get :

Hence, this is the required solution.