CHEMISTRY COLLEGE

A student was asked to prepare exactly 250 mL of a 0.500 M aqueous potassium hydroxide solution. What mass of potassium hydroxide (molar mass = 56.10 g/mol) must the student dissolve in the 250 mL of solution? 1. 28.1 g 2. 3.0 g 3. None of these 4. 14.0 g 5. 7.01 g 6. 56.1 g

Answers

Answer 1

Answer:

Answer:

Option 5 → 7.01 g

Explanation:

Molarity . volume (L) = Moles

This can help us to determine the moles of KOH that are in the solution.

We convert the volume from mL to L → 250 mL . 1L / 1000mL = 0.250 L

0.5 mol /L . 0.250L = 0.125 moles of KOH

Now, we only have to convert the moles to mass, by the molar mass:

Moles . molar mass = mass → 0.125 mol . 56.1 g/mol = 7.01 g

Answer 2

Answer:

Answer:

We need 7.01 grams of KOH (option 5)

Explanation:

Step 1: Data given

Volume aqueous KOH solution = 250 mL = 0.250 L

Molarity = 0.500 M

Molar mass of KOH = 56.10 g/mol

Step 2: Calculate moles KOH

Moles KOH = molarity * volume

Moles KOH = 0.500 M * 0.250 L

Moles KOH = 0.125 moles

Step 3: Calculate mass of KOH

Mass KOH = moles KOH * molar mass KOH

Mass KOH = 0.125 moles * 56.10 g/mol

Mass KOH = 7.01 grams

We need 7.01 grams of KOH

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Answers

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Why does a voltmeter not accurately read voltage?

because the voltmeter uses some of the main circuit's current. Main present in the circuit diminishes as a result, and the voltmeter's reading of the potential difference does not correspond to its true value.

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This section of the periodic table is called a(n)

Answers

Answer:

Is it Group?

Explanation:

Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

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Answers

Considering the formation of a chemical formula, the chemical formula is Li₂O.

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Cations (positivelycharged ions) and anions (negatively charged ions) combine to form ionic compounds, which must be electrically neutral. Therefore, the cations and anions must combine in such a way that the net charge contributed by the total number of cations exactly cancels the net charge contributed by the total number of anions.

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It is first necessary to place the chemical symbol of the element that is a cation, and then the negative part (anion).
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Chemical formula in this case

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Answer:

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Explanation:

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