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2 years ago

What is atom.

Chemistry

1 answer:

katovenus [111]2 years ago

3 0

Answer:

atom is the smallest indivisible particle of an element

Explanation:

The symbol of 20 element are H He li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

element is the simplest pure form of a substance .

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An unknown diprotic acid (H2A) requires 44.391 mL of 0.111 M NaOH to completely neutralize a 0.58 g sample. Calculate the approx

Anna [14]

Answer:

$M=235.42g/mol$

Explanation:

Hello!

In this case, given this is an acid-base neutralization and we are considering a diprotic acid, we can write the following mole-mole relationship:

$2n_{acid}=n_{base}$

It means that the moles of acid can be computed given the volume and concentration of NaOH:

$n_{acid}=\frac{M_{base}V_{base}}{2} =\frac{0.044391L*0.111mol/L}{2} \\\\n_{acid}=2.46x10^{-4}mol$

It means that the approximate molar mass of the acid is:

$M=\frac{m_{acid}}{n_{acid}} \\\\M=\frac{m_{acid}}{n_{acid}} =\frac{0.58g}{2.46x10^{-3}mol}\\\\M=235.42g/mol$

Best regards!

5 0

3 years ago

3.7x10^7 and 3.30x10^8 written in scientific notation

kodGreya [7K]

Answer:

1) 37100000

2) 330000000

Explanation:

1) 3.7 x 10^7 = 37100000

2) 3.30 x 10^8 = 330000000

(Hope this helps can I pls have brainlist (crown)☺️)

3 0

3 years ago

er solutions can be produced by mixing a weak acid with its conjugate base or by mixing a weak base with its conjugate acid. The

liubo4ka [24]

Answer:

You need to add 19,5 mmol of acetates

Explanation:

Using the Henderson-Hasselbalch equation:

pH = pKa + log₁₀ [base]/[acid]

For the buffer of acetates:

pH = pKa + log₁₀ [CH₃COO⁻]/[CH₃COOH]

As pH you want is 5,03, pka is 4,74 and milimoles of acetic acid are 10:

5,03 = 4,74 + log₁₀ [CH₃COO⁻]/[10]

1,95 = [CH₃COO⁻]/[10]

<em>[CH₃COO⁻] = 19,5 milimoles</em>

Thus, to produce an acetate buffer of 5,03 having 10 mmol of acetic acid, you need to add 19,5 mmol of acetates.

I hope it helps!

7 0

3 years ago

Which of the following ratios are needed to determine the mass of oxygen produced from the decomposition of 10 grams of potassiu

Zielflug [23.3K]

The ratios which are needed to determine the mass of oxygen produced from the decomposition of 10 grams of potassium chlorate are;

31.998 g O2 : 1 mole O2
3 mole O2 : 2 mole KClO3
112.55 g KClO31 mole KClO3

From stoichiometry;

We can conclude that according to the reaction;

3 moles of oxygen requires 2 moles of KClO3 to be produced.

And from molar mass analysis;

31.998 g O2 is equivalent to 1 mole O2
O2112.55 g KClO3 is equivalent to 1 mole KClO3

brainly.com/question/9920155

7 0

3 years ago

Which electron transition results in the emission of energy

Yuki888 [10]

Energy is emitted when an electron falls from a higher energy level to a lower one.

The transition from 3p to 3s would emit energy because the 3s sublevel is lower than the 3p.

3 0

3 years ago