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3 years ago

Does anyone have the 2020 paper for chemistry

Chemistry

1 answer:

timama [110]3 years ago

6 0

Answer:

Erm.......... can you clarify what "paper", you just said "paper" there's a lot.

Explanation:

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An unknown concentration of sodium thiosulfate, Na2S2O3, is used to titrate a standardized solution of KIO3 with excess KI prese

Maru [420]

Answer: The molarity of $Na_2S_2O_3$ is 0.108 M

Explanation:

$KIO_3+5KI+3H_2SO_4\rightarrow 3K_2SO_4+3H_2O+3I_2$

$2Na_2S_2O_3+I_2\rightarrow Na_2S_4O_6+2NaI$

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

$\text{Moles of }KIO_3=\frac{0.0131mol/L\times 21.55}{1000}=2.8\times 10^{-4}mol$

1 mole of $KIO_3$ produces = 3 moles of $I_2$

$2.8\times 10^{-4}$ moles of $KIO_3$ produces = $\frac{3}{1}\times 2.8\times 10^{-4}=8.4\times 10^{-4}$ moles of $I_2$

Now 1 mole of $I_2$ uses = 2 moles of $Na_2S_2O_3$

$8.4\times 10^{-4}$ moles of $I_2$ uses = $\frac{2}{1}\times 8.4\times 10^{-4}=1.69\times 10^{-3}$ moles of $Na_2S_2O_3$

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution in L}}=\frac{1.69\times 10^{-3}\times 1000}{15.65}=0.108M$

The molarity of $Na_2S_2O_3$ is 0.108 M

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3 years ago

Which of the following is the same as a beta particle?

IceJOKER [234]

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C. Digestion is the answer.

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musickatia [10]

The elements that compose it and the arrangement of its atoms.

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