$CATEGORY: Science - Khan Academy/2.Acids, Bases and Salts/2.Acids, Bases and Salts--how strong are acid or base solutions

//Multiple Choice

What happens to the pH if the concentration of H⁺ ions increases?
{
~ pH increases
= pH decreases
~ pH remains constant
~ No change in pH
}

What is the pH of a neutral solution at 25°C?
{
~ 5
= 7
~ 10
~ 14
}

If the concentration of OH⁻ ions increases, the solution becomes\:
{
~ Neutral
~ Acidic
= Basic
~ No change
}

If the pH of a solution changes from 5 to 3, the H⁺ ion concentration\:
{
~ Becomes half
~ Becomes 10 times
= Becomes 100 times
~ Remains the same
}

What is the relationship between pH and pOH?
{
= pH + pOH \= 14
~ pH × pOH \= 14
~ pH - pOH \= 7
~ None of the above
}

//True or False

A solution with a pH of 8 is acidic. {F}

A decrease in OH⁻ concentration increases the pH. {F}

If the concentration of H⁺ ions doubles, the pH decreases by 0.3 units. {T}

The pH scale ranges from 0 to 14 for most solutions. {T}

A solution with pH \= 7 is neutral at all temperatures. {F}

//Fill in the blanks

A decrease in pH indicates an increase in the concentration of ______ ions.
{
= H⁺
~ H⁻
~ O⁺
}

If the concentration of OH⁻ ions decreases, the solution becomes more ______.
{
~ Basic
= Acidic
~ Neutral
}

The pH of a solution is calculated using the formula pH \= ______.
{
~ -log[H⁻]
~ -log[H]
= -log[H⁺]
}

At 25°C, the product of [H⁺]×[OH⁻] is always ______.
{
= 10⁻¹⁴
~ 10⁻¹⁵
~ 10⁻¹⁶
}

An increase in the pH value means the solution is becoming more ______.
{
~ Acidic
~ Neutral
= Basic
}

//Numericals



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=pH 7 -> Neutral
=pH less than 7 -> Acidic
=pH greater than 7 -> Basic
=Increase in H⁺ concentration -> Decrease in pH
=Increase in OH⁻ concentration -> Increase in pH
}


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