According to Arrhenius theory, a base is anything that creates _________________ as the only __________ ion in aqueous solution.
Hydroxide, negative
100
What indicators are good for titrations and why?
Phenolphthalein, bromthymol blue, and maybe litmus are all reasonable because they change around or near a pH of 7, which is neutral.
100
Why is it important to stop a titration using phenolphthalein at a light pink color?
The pH is light pink from 8-9, which is close to neutral. Dark pink could be any pH above 9 and would be much too basic.
100
Which metals will not react will acid to produce hydrogen gas?
Cu, Ag, & Au (copper, silver, and gold)
100
The pH of neutral water should be . . .
7
200
According to Arrhenius theory, an acid is anything that creates __________________ or __________as the only __________ ion in aqueous solution.
Hydronium, Hydrogen, positive
200
A solution that has a pH of 4.0 is tested first with litmus and then with methyl orange. What colors are observed?
red, orange
200
An acid is in an ehrlenmeyer flask being titrated against a base from a buret. As the base is added, the hydronium ion concentration . . .
The hydronium ion concentration drops because it is being neutralized by hydroxide ions from the base, forming water.
200
What is the word equation for neutralization?
acid + base -> water + salt
200
What pH solution would have the highest hydronium ion concentration?
2, 5, 7, 12, or 14
A pH of 2 would be the most acidic, and therefore have the highest hydronium ion concentration.
300
A student tests an unknown liquid and find that is an electrolyte and turns methyl orange yellow. They conclude that it is a base. Are they right? Explain.
This is not enough information. Acids, bases, and salts are all electrolytes and methyl orange is yellow at any pH above 4.4 so it could be anything.
300
A substance conducts electricity, turns blue litmus red, and reacts with a metal to form hydrogen gas. It could be . . .
LiOH, CH3COOH, KCl, or NH3
CH3COOH (acetic acid)
300
What molarity of HCl would be neutralized by 15.00mL of 0.204M NaOH, if 25.00mL were used? Show the setup and the answer.
(x)(25.00mL)=(0.204M)(15.00mL)
Ma=0.122M
300
Finish the word equation: A reaction between nitric acid and lithium hydroxide will produce _________________ and ________________.
water and lithium nitrate
300
What pH would have 1/100th the OH- ion concentration of a solution with a pH of 8?
6
400
Identify all the following as either acid or base:
*hydrogen ion
*hydronium ion
*hydroxide ion
*H+ acceptor
*H+ donor
Which solution could have the highest hydroxide ion concentration?
*a solution that turns methyl orange yellow
*a solution that turns bromcresol green blue
*a solution that turns thymol blue blue
A solution that turns thymol blue blue would have a pH above 9.6 and could be the most basic, having the highest hydroxide ion concentration.
400
Buret readings HBr LiOH (0.100M)
initial volume (mL) 12.00 19.50
final volume (mL) 21.50 47.50
Find the unknown concentration. Show the setup and answer.
(X)(9.50mL)=(0.100M)(28.00mL)
Ma=0.295M
400
Write the balanced reaction that happens between sulfuric acid and potassium hydroxide.
H2SO4 + 2KOH -> 2HOH + K2SO4
400
A solution with a pH of 9 has its hydroxide ion concentration increased 1000-fold. What is the new pH?
12
500
In the reaction HCl + NH3 -> Cl- + NH4+, Which is the base and why?
NH3 is the base because it is an H+ acceptor
500
Two samples of the same rainwater are tested using two indicators. Methyl Orange is yellow in one sample. Litmus is red in the other. Identify the specific possible pH range for the rainwater.
4.4 - 4.5
500
Buret readings KOH HNO3 (0.42M)
initial volume (mL) 19.50 4.50
final volume (mL) 25.50 22.00
Find the unknown concentration. Show the setup and answer.
(0.42M)(17.50mL)=(x)(6.00mL)
Ma=1.2M
500
50.0mL of NaOH is titrated against 0.20M H2SO4. After 35.0mL of the acid is added a color change happens. What is the molarity of the base. Show the setup and answer.
(0.40M)(35.0mL)=(x)(50.0mL)
NB: the Molarity of sulfuric acid is DOUBLED because it has two hydrogen ions!
Mb=0.28M
500
A truck carrying concentrated nirtic acid overturns and spills its contents. The acid drains into a nearby pond the pH of the pond water was 8.0 before the spill. After the spill, the hydronium ion concentration is 1000 times higher. What is the new pH and what color will bromthymol blue be at this new pH?