Answer:
5.9 × 10^-6.
Explanation:
In the arrangements of crystal solids there is likely going to be an imperfection or defect and one of the defect or imperfections in the arrangements of solids is known as the Schottky defects. The Schottky defects is a kind of lattice arrangements imperfection that occurs when positively charged ions and negatively charged ions leave their position.
So, let us delve right into the solution of the question. We will be making use of the formula below;
Wb/ W = e^ - c/ 2kT.
Where Wb/ W= fraction of lattice sites, c= energy for defect formation = 1.86 eV, and T = temperature= 623° C= 896 k.
So, Wb/ W = e ^ -1.86/ (2 × 896 × 8.62 × 10^ -5).
Wb/ W= 0.000005896557435956372.
Wb/ W=5.9 × 10^-6.
Answer:
0.0526mol
Explanation:
The chemical equation given in this equation is as follows:
Na3PO4 + Sr(NO3)2 → Sr3(PO4)2 + NaNO3
However, this equation is unbalanced as the number of atoms of each element on each side does not correlate. The balanced equation is as follows:
2Na3PO4 + 3Sr(NO3)2 → Sr3(PO4)2 + 6NaNO3
This balanced equation means that:
2 moles of Sodium Phosphate (Na3PO4) is required to react with 3 moles of Strontium Nitrate (Sr(NO3)2)
Hence, if 0.0789 moles of Strontium Nitrate are reacted, then 0.0789 × 2/3
moles of sodium phosphate will also react.
= 0.0789 × 2/3
= 0.1578/3
= 0.0526mol
CH4 (g) + 2O2 (g) --> CO2 (g) + 2H2O (i)
at STP, 1 mol gas = 22.4 L gas. so you have 52.0 L / 22.4 L / mol = 2.32 mol CH4.
According to the balanced reaction, you need 2 mol O2 for every 1 mol CH4. so you need 2 x 2.32 mol = 4.64 mol O2.
hope this help
I think the correct answer from the choices listed above is option C. The substances that do not undergo chemical change when mixed are the substances NaNO3(aq) and KI(aq). They form spectator ions. Hope this answers the question.
