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2 years ago

HELPPP!!!

Chemistry

1 answer:

dedylja [7]2 years ago

5 0

Hydropower is one of the oldest renewable resources and has been used for thousands of years.

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A reaction of 41.9 g of Na and 30.3 g of Br2 yields 36.4 g of NaBr . What is the percent yield?

Licemer1 [7]

Answer: The percent yield is, 93.4%

Explanation:

First we have to calculate the moles of Na.

$\text{Moles of Na}=\frac{\text{Mass of Na}}{\text{Molar mass of Na}}=\frac{41.9g}{23g/mole}=1.82moles$

Now we have to calculate the moles of $Br_2$

${\text{Moles of}Br_2} = \frac{\text{Mass of }Br_2 }{\text{Molar mass of} Br_2} =\frac{30.3g}{160g/mole}=0.189moles$

${\text{Moles of } NaBr} = \frac{\text{Mass of } NaBr }{\text{Molar mass of } NaBr} =\frac{36.4g}{103g/mole}=0.353moles$

The balanced chemical reaction is,

$2Na(s)+Br_2(g)\rightarrow 2NaBr$

As, 1 mole of bromine react with = 2 moles of Sodium

So, 0.189 moles of bromine react with = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium

Thus bromine is the limiting reagent as it limits the formation of product and Na is the excess reagent.

As, 1 mole of bromine give = 2 moles of Sodium bromide

So, 0.189 moles of bromine give = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium bromide

Now we have to calculate the percent yield of reaction

$\%\text{ yield}=\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100=\frac{0.353 mol}{0.378}\times 100=93.4\%$

Therefore, the percent yield is, 93.4%

3 0

3 years ago

What do you think is meant by the phrase "a balanced diet"?

Maurinko [17]

To have the right combinations of foods to provide nutrients

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3 years ago

f. . A metal cylinder has a mass of 100.00 g is heated to 95.50 celcius and then put in 245.5 g of water whose initial temperatu

Murljashka [212]

$\large\colorbox{orange}{May Be Helpful ✌️ Dear ✌️}$ $\large\colorbox{orange}{May Be Helpful ✌️ Dear ✌️}$

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3 years ago

Help me guys please i need help

bearhunter [10]

Answer:

It helps microorganisms grow

Explanation:

I think this is the correct answer because I tried searching it up and you sterilise the petri dish before adding the agar, I've used agar in petri dishes a year ago and im pretty sure they don't make cells glow or make bacteria appear larger.

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2 years ago

A container holds a sample of hydrogen gas at 300 K. The temperature decreased to 100 K and the pressure remained constant, and

Charra [1.4K]

Answer : The original volume of gas was, 3.0 L

Explanation :

Charles' Law : It is defined as the volume is directly proportional to the temperature of the gas at constant pressure and number of moles.

$V\propto T$