Answer:
First one: group
Second one: period
Third one: number of valence electrons
Last one: increases
Answer:
HF is the limiting reactant
Explanation:
The balanced equation for the reaction is given below:
SiO₂ + 4HF —> SiF₄ + 2H₂O
From the balanced equation above,
1 mole of SiO₂ reacted with 4 moles of HF.
Finally, we shall determine the limiting reactant. This can be obtained as illustrated below:
From the balanced equation above,
1 mole of SiO₂ reacted with 4 moles of HF.
Therefore, 7.5 moles of SiO₂ will react with = 7.5 × 4 = 30 moles of HF.
From the calculation made above, we can see clearly that it will take a higher amount (i.e 30 moles) of HF than what was given from the question (i.e 5 moles) to react completely with 7.5 moles of SiO₂.
Therefore, HF is the limiting reactant and SiO₂ is the excess reactant.
Answer:
It's 23.14 percent
Explanation:
First, the mass of all the elements are:
N = 14
O = 16
Fe = 56
In this molecule you have 3 atoms of N, and 9 atoms of O, so:
3•14 = 42
16•9 = 144
The whole mass of the molecule is:
56 + 42 + 144 = 242
242/100 = 2.42, so 1% is 2.42
56/2.42 = 23.14%
The chemical reaction would most likely be written as follows:
A + B = AB
We cannot simply use the usual method of converting grams to moles since we do not have any idea on what are the identities of A and B. The only method we could use is to use the law of conservation of mass where mass inflow in a process should be equal to the mass out in the process. The total inflow of mass would be the mass of A and B and the outflow would be the product AB.
mass of A + mass of B = mass of AB
10.0 g A + 10.0 g B = mass of AB
mass of AB = 20.0 g
