Answer:
24.525 g of sulfuric acid.
Explanation:
Hello,
Normality (units of eq/L) is defined as:

Since the sulfuric acid is the solute, and we already have the volume of the solution (500 mL) but we need it in liters (0.5 L, just divide into 1000), the equivalent grams of solute are given by:

Now, since the sulfuric acid is diprotic (2 hydrogen atoms in its formula) 1 mole of sulfuric acid has 2 equivalent grams of sulfuric acid, so the mole-mass relationship is developed to find its required mass as follows:

Best regards.
I'd guess A or D, but my gut says A
Answer:
B. Equal to 7.
Explanation:
Hydrobromic acid is a strong acid that decreases pH and ammonia is a strong base that increases pH.
As the initial pH of water is 7,0 the addition of 35.0mL of 0.400M HBr will produce a pH less than 7,0. But, the same effect of decreasing pH is reverted for the addition of 35.0mL of 0.400M HNO3.
That means the net effect of the two addition is to have a pH:
B. Equal to 7.
I hope it helps!
Answer : The final temperature of the mixture is 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of iron = 
= specific heat of water = 
= mass of iron = 39.9 g
= mass of water = 
= final temperature of mixture = ?
= initial temperature of iron = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the final temperature of the mixture is 
It takes exactly 500 seconds for the sun's radiation to reach the earth or about 8 minutes (8.333333333333... to be exact). Just divide 150 million km by 300,000 km/s. Hope this helps