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3 years ago

(Science)

Chemistry

2 answers:

Naily [24]3 years ago

8 0

It would be the Permian period

kramer3 years ago

7 0

The permian period because right after that are the triassic, jurassic, and cretaceous periods, which are known for the dinosaurs . hope this helps!!

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Following the instructions in your lab manual, you have titrated a 25.00 mL sample of 0.0100 M KIO3 with a solution of Na2S2O3 o

vivado [14]

Answer:

For 1: The amount of potassium iodate that were titrated is $2.5\times 10^{-4}$ moles

For 2: The amount of sodium thiosulfate required is $1.25\times 10^{-4}$ moles

Explanation:

For 1:

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

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}$

Molarity of $KIO_3$ solution = 0.0100 M

Volume of solution = 25 mL

Putting values in above equation, we get:

$0.0100M=\frac{\text{Moles of }KIO_3\times 1000}{25}\\\\\text{Moles of }KIO_3=\frac{0.0100\times 25}{1000}=0.00025mol$

Hence, the amount of potassium iodate that were titrated is $2.5\times 10^{-4}$ moles

For 2:

The chemical equation for the reaction of potassium iodate and sodium thiosulfate follows:

$2KIO_3+Na_2S_2O_3\rightarrow K_2S_2O_3+2NaIO_3$

By Stoichiometry of the reaction:

2 moles of potassium iodate reacts with 1 mole of sodium thiosulfate

So, 0.00025 moles of potassium iodate will react with = $\frac{1}{2}\times 0.00025=0.000125mol$ of sodium thiosulfate

Hence, the amount of sodium thiosulfate required is $1.25\times 10^{-4}$ moles

6 0

3 years ago

How many moles of hydrogen gas will be produced if 5.00 moles of zinc reactions with an excess amount of sulfuric acid

harkovskaia [24]

Answer:

Moles of Hydrogen produced is 5 moles

Explanation:

The balanced Chemical equation for reaction between zinc and sulfuric acid is :

$Zn(s) + H_{2}SO_{4}(aq) \rightarrow ZnSO_{4}(aq) + H_{2}(g)$

This equation tells that ; when 1 mole of Zn react with 1 mole of sulfuric acid, it produces 1 mole of zinc sulfate and 1 mole of hydrogen.

Since sulfuric acid is in excess so Zinc is the limiting reagent

(Limiting reagent : Substance which get consumed when the reaction completes, limiting reagent helps in predicting the amount of products formed)

Limiting reagent (Zn) will decide the amount of Hydrogen produced

$Zn(s) + H_{2}SO_{4}(aq) \rightarrow ZnSO_{4}(aq) + H_{2}(g)$

$1\ mole\ zinc\rightarrow 1\ mole\ H_{2}$

So,

$5\ mole\ zinc\rightarrow 5\ mole\ H_{2}$

Hence moles of Hydrogen produced is 5 moles

3 0

3 years ago

What affect does attendance have on students' grades in science class? Write the independent variable, the dependent variable, a

alexira [117]

Independent variable: the student chooses to miss class.
dependent variable: in result of the student missing class his grade goes down.
hyposthesis: if the student misses class multiple times, then his grades will go down.

6 0

3 years ago

What is the final volume of a gas (in liters) when the initial volume is 14.00 L at

8_murik_8 [283]

Answer:

$V_2=1344L$

Explanation:

Hello there!

In this case, since we have a problem about volume-pressure relationship, the idea here is to use the Boyle's law to calculate the final volume as shown below:

$P_2V_2=P_1V_1\\\\V_2=\frac{P_2V_2}{P_1}\\$

Then, we plug in the initial and final pressures and the initial volume to obtain:

$V_2=\frac{14.00L*0.9600atm}{0.01000atm}\\\\V_2=1344L$

Regards!

4 0

2 years ago

Which of the following are elements? O2 Ca KF B

ASHA 777 [7]

Ca is the only element perhaps B

6 0

3 years ago

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