Answer:
0.25M HCl
Explanation:
The reaction of HCl with NaOH is:
HCl + NaOH ⇄ H₂O + NaCl
<em>Where 1 mole of HCl reacts per mole of NaOH</em>
The end point was reached when the student added:
0.0500L × (0.1mol / L) = 0.00500 moles of NaOH
As 1 mole of HCl reacted per mole of NaOH, moles of HCl present are:
<em>0.00500 moles HCl</em>
The volume of the sample of hydrochloric acid was 20.0mL = 0.0200L, and concentration of the sample is:
0.00500 mol HCl / 0.0200L = <em>0.25M HCl</em>
Answer:
The amount of base needed is the amount that would give one mole of the hydroxide ion needed to neutralise one mole of the hydroxonium ion from the acid.
Explanation:
The chemical reaction between an acid and a base to form salt and water only is called a Neutralization reaction. Chemically
H⁺ + OH⁻ = H₂0
Hence, one mole of hydroxonium ion (H⁺) will combine with one mole of hydroxide ion (OH⁻) to give salt and water only.
In a completely neutralized reaction, the resulting salt is formed when there is complete dissociation of the acid and base to give salt and water with a pH of 7.
In the given question, the stated pH of between 8-9 tells us that the salt produced in this particular neutralization reaction is basic or alkaline. This usually occurs when a strong base reacts with a weak acid, producing a higher concentration of the hydroxide ion at equilibrium.
Hence the amount of base needed is the amount that would give one mole of the hydroxide ion needed to neutralise one mole of the hydroxonium ion from the acid.
If the concentration or molarity of the acid is known, then the exact amount of base required to neutralize it can be calculated. This is usually done via titrating the acid against drop wise solution of the base. Neutralization usually occurs when there is a change in colour of the resulting solution. The pH of the resulting solution can be determined using a litmus paper.
A blue litmus paper is indicative of a basic solution while a red litmus paper is indicative of an acidic solution.
Answer:
<h3>Saponification is a process that involves conversion of fat, oil or lipid into soap and alcohol by the action of heat in the presence of aqueous alkali. Soaps are salts of fatty acids and fatty acids are monocarboxylic acids that have long carbon chains e.g. sodium palmitate.</h3>
Answer:
B: increase.
Explanation:
When we are considering two gases A and B in a container at room temperature .
We have to find the change on rate of reaction when the number of molecules of gases A is doubled
Let [A]=a and [B]=b
A+B
product
Rate of reaction
![R_1=k[A][B]=kab](https://tex.z-dn.net/?f=R_1%3Dk%5BA%5D%5BB%5D%3Dkab)
We know that concentration is increases with increase in number of moles
When the number of molecules of gases A is doubled then concentration of gases A increases.
Therefore ,[A]=2a
Rate of reaction
Hence, the rate of reaction is 2 times the initial rate of reaction.Therefore, the rate of reaction will increase when the number of molecules of gases A is doubled.
Answer: B: increase.
16.4 grams is the mass of solute in a 500 mL solution of 0.200 M
.
sodium phosphate
Explanation:
Given data about sodium phosphate
atomic mass of Na3PO4 = 164 grams/mole
volume of the solution = 500 ml or 0.5 litres
molarity of sodium phosphate solution = 0.200 M
The formula for molarity will be used here to know the mass dissolved in the given volume of the solution:
The formula is
molarity = 
putting the values in the equation, we get
molarity x volume = number of moles
0.200 X 0.5= number of moles
number of moles = 0.1 moles
Atomic mass x number of moles = mass
putting the values in the above equation
164 x 0.1 = 16.4 grams
16.4 grams of sodium phosphate is present in 0.5 L of the solution to make a 0.2 M solution.
