<span>In my opinion, it is a rotten question, phrased as it is. It all depends on how much acid and how much base. It also depends on the type of acid (sulfuric acid reacts differently than hydrochloric - sulfuric has two atoms of hydrogen compared to hydrochloric which has one atom of hydrogen per molecule). It also can depend on the concentration - for example, if you're mixing a one molar solution of acid with a two molar solution of base, and on how much you are mixing - if you are mixing one liter of base with one liter of acid, or whatever. Your instructor needs to establish these things in order to make it a question you can actually answer.
But, your instructor probably means what happens if you add the same amount of an acid and a base together, and they have the same strength. Ideally, if you mix the same amounts of an acid and a base, and the acid has one atom of hydrogen, then you would get water plus a salt, which would have a neutral pH.
For example, HCl + NaOH, mixed in the same amounts and at the same concentrations would give you HOH (or water) plus NaCl (which is actually table salt). All acids and bases that are mixed in these equal concentrations always give you water plus a salt (although not always table salt - just what is chemically known as a "salt).</span>
Is this a multiple choice? Anyways I will just give you a written answer and hopefully it helps.
A: Helium is made up of two electrons held by electromagnetic force to two protons that are inside of a nucleus along with one or two neutrons.
Not sure which one you wanted, so here a few different ones:
<u>Decimal notation:</u> 5.00
<u>Scientific notation:</u> 5.00 × 
<u>E notation:</u> 5.00e+0
<u>Answer:</u>
<u>For a:</u> The empirical formula of the compound is 
<u>For b:</u> The empirical formula of the compound is 
<u>Explanation:</u>
We are given:
Percentage of P = 43.6 %
Percentage of O = 56.4 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of P = 43.6 g
Mass of O = 56.4 g
To formulate the empirical formula, we need to follow some steps:
- <u>Step 1:</u> Converting the given masses into moles.
Moles of Phosphorus =
Moles of Oxygen = 
- <u>Step 2:</u> Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 1.406 moles.
For Phosphorus = 
For Oxygen = 
Converting the moles in whole number ratio by multiplying it by '2', we get:
For Phosphorus = 
For Oxygen = 
- <u>Step 3:</u> Taking the mole ratio as their subscripts.
The ratio of P : O = 2 : 5
Hence, the empirical formula for the given compound is 
We are given:
Percentage of K = 28.7 %
Percentage of H = 1.5 %
Percentage of P = 22.8 %
Percentage of O = 56.4 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of K = 28.7 g
Mass of H = 1.5 g
Mass of P = 43.6 g
Mass of O = 56.4 g
To formulate the empirical formula, we need to follow some steps:
- <u>Step 1:</u> Converting the given masses into moles.
Moles of Potassium =
Moles of Hydrogen =
Moles of Phosphorus =
Moles of Oxygen = 
- <u>Step 2:</u> Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.735 moles.
For Potassium = 
For Hydrogen = 
For Phosphorus = 
For Oxygen = 
- <u>Step 3:</u> Taking the mole ratio as their subscripts.
The ratio of K : H : P : O = 1 : 2 : 1 : 4
Hence, the empirical formula for the given compound is 
At 40 degrees Celsius, approximately 78 grams of potassium bromide can be dissolved.