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1 year ago

Question 1

Chemistry

1 answer:

lisov135 [29]1 year ago

8 0

Answer:

24+74+61+29+38+27+68+54= 375

then divide by the number of numbers in this case 8 so;

375/8= 46.875

<h2>that's the median 46.875</h2>

Explanation:

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An unknown amount of acid can often be determined by adding an excess of base and then back-titrating the excess. A 0.3471−g sam

MAXImum [283]

Explanation:

The given data is as follows.

Mass of mixture = 0.3471 g

As the mixture contains oxalic acid and benzoic acid. So, oxalic acid will have two protons and benzoic acid has one proton.

This means oxalic acid will react with 2 moles of NaOH and benzoic acid will react with 1 mole of NaOH.

Hence, moles of NaOH in 97 ml = $\frac{0.1090 \times 97}{1000}$

= $10.573 \times 10^{-3} mol$

Moles of HCl in 21.00 ml = $\frac{0.2060 \times 21}{1000}$

= $4.326 \times 10^{-3}$ mol

Therefore, total moles of NaOH that reacted are as follows.

$10.573 \times 10^{-3} mol$ - $4.326 \times 10^{-3} mol$

= $6.247 \times 10^{-3}$ mol

So, total 3 mole of NaOH will react with 1 mole of mixture. Therefore, number of moles of NaOH reacted with benzoic acid is as follows.

$\frac{6.247 \times 10^{-3}}{3}$

= $2.082 \times 10^{-3}$ mol

Since, molar mass of NaOH is 40 g/mol. Therefore, calculate the mass of NaOH as follows.

$2.082 \times 10^{-3} mol \times 40 g/mol$

= $83.293 \times 10^{-3}$ g

= 0.0832 g

Whereas molar mass of benzoic acid is 122 g/mol.

Therefore, 40 g NaOH = 122 g benzoic acid

So, 0.0832 g NaOH = $\frac{122 g}{40 g} \times 0.0832 g$

= 0.253 g

Hence, calculate the % mass of benzoic acid as follows.

$\frac{0.253 g}{0.3471 g} \times 100$

= 73.10%

Thus, we can conclude that mass % of benzoic acid is 73.10%.

4 0

3 years ago

The amount of radioactive carbon-14 in a sample is measured using a Geiger counter, which records each disintegration of an atom

sergij07 [2.7K]

Answer:

4121 years

Explanation:

From;

0.693/t1/2 = 2.303/t log No/N

t1/2= half life of the carbon-14

No= count rate of the living tissue

N= count rate of the sample

t = age of the sample

0.693/5730 =2.303/t log (13.5/8.2)

1.21 * 10^-4 = 2.303/t * 0.2165

1.21 * 10^-4 = 0.4986/t

t = 0.4986/1.21 * 10^-4

t = 4121 years

7 0

3 years ago

(HELP ME ASAP!)

slega [8]

A) Ca(OH)2 + CO2 —> CaCO3 + H2O

B) when Ca(OH)2 is reacted with CO2, the CaCO3 produced is a precipitate which turns the solution milky

8 0

3 years ago

Open the Balancing Chemical Equations interactive and select Introduction mode. Then choose Separate Water. Adjust the coefficie

aleksklad [387]

Explanation:

1. Water decomposition

Decomposition reactions are represented by-

The general equation: AB → A + B.

Various methods used in the decomposition of water are -

Electrolysis
Photoelectrochemical water splitting
Thermal decomposition of water
Photocatalytic water splitting

Water decomposition is the chemical reaction in which water is broken down giving oxygen and hydrogen.

The chemical equation will be -

$H_2O + H_2 + O_2$

Hence, balancing the equation we need to add a coefficient of 2 in front of $H_2O$ on right-hand-side of the equation and 2 in front of $H_2$ on left-hand-side of the equation.

∴The balanced equation is -

$2 H_2O$ → $2 H_2 + O_2$

2. Formation of ammonia

The formation of ammonia is by reacting nitrogen gas and hydrogen gas.

$N_2 + H$ → $NH_3$

Hence, for balancing equation we need to add a coefficient of 3 in front of hydrogen and 2 in front of ammonia.

∴The balanced chemical equation for the formation of ammonia gas is as follows -

$N_2+3H$ → $2NH_3$ .

When 6 moles of $N_2$ react with 6 moles of $H_2$ 4 moles of ammonia are produced.

5 0

2 years ago

Help help help.

Whitepunk [10]

I think B
Hope this helps!

4 0

3 years ago