Answer:
Here's what I find.
Explanation:



The sign of ΔH changes when you reverse the reaction.
I think silicon(Si) is the best example of semiconductors
Answer:
There are 3 significant figures in 675000
Explanation:
The rules for significant figures:
- Non zero digit (from 1 upward) are always significant
- Trailing zero are not significant
- but zero in the presence of decimal are significant
In this case, the trailing zeros are not significant thus only the first 3 non zero digit are significant.
From the calculation, the pH of the solution is 4.85.
<h3>What is the pH?</h3>
The pH is defined as the hydrogen ion concentration of the solution. We have the ICE table as;
HA + H2O ⇔ H3O^+ + A^-
I 0.335 0 0
C -x +x +x
E 0.335 - x x x
Ka = 1 * 10^-14/Kb
Ka = 1 * 10^-14/1.8 × 10^–5
Ka = 5.56 * 10^-10
Ka = [H3O^+] [A^-]/[HA]
But [H3O^+] = [A^-] = x
5.56 * 10^-10 = x^2/ 0.335 - x
5.56 * 10^-10(0.335 - x ) = x^2
1.86 * 10^-10 - 5.56 * 10^-10x = x^2
x^2 + 5.56 * 10^-10x - 1.86 * 10^-10 = 0
x=0.000014 M
Now;
pH = -log 0.000014 M
pH = 4.85
Learn more about pH:brainly.com/question/15289741
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The Correct answer is Carbon dioxide CO2.
The Explanation:
according to the diagram:
we can see that the arrows which going to A are from:
1- respirition of the tree . and the CO2 gas is the result and produced gas from respiration.
2- The Combustion went from Home : and the CO2 gas is also the produced gas from the combustion process.
∴ (A) refers to CO2 (carbon dioxide) gas.