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3 years ago

Can the excess reactant (in stoichiometry) be negative?

1 answer:

6 0

No. Think about it this way: it’s a physical, leftover substance, you can never have a negative amount of anything.

If you’re speaking in terms of charge, however, then yes, it’s very likely.

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Determine the theoretical yield of HCl if 60.0 g of BC13 and 37.5 g of H20 are reacted according to the following balanced react

Pie

Answer : The theoretical yield of HCl is, 56.1735 grams

Explanation : Given,

Mass of $BCl_3$ = 60 g

Mass of $H_2O$ = 37.5 g

Molar mass of $BCl_3$ = 117 g/mole

Molar mass of $H_2O$ = 18 g/mole

Molar mass of $HCl$ = 36.5 g/mole

First we have to calculate the moles of $BCl_3$ and $H_2O$ .

$\text{Moles of }BCl_3=\frac{\text{Mass of }BCl_3}{\text{Molar mass of }BCl_3}=\frac{60g}{117g/mole}=0.513moles$

$\text{Moles of }H_2O=\frac{\text{Mass of }H_2O}{\text{Molar mass of }H_2O}=\frac{37.5g}{18g/mole}=2.083moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$BCl_3(g)+3H_2O(l)\rightarrow H_3BO_3(s)+3HCl(g)$

From the balanced reaction we conclude that

As, 1 mole of $BCl_3$ react with 3 mole of $H_2O$

So, 0.513 moles of $BCl_3$ react with $3\times 0.513=1.539$ moles of $H_2O$

From this we conclude that, $H_2O$ is an excess reagent because the given moles are greater than the required moles and $BCl_3$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $HCl$ .

As, 1 mole of $BCl_3$ react to give 3 moles of $HCl$

So, 0.513 moles of $BCl_3$ react to give $3\times 0.513=1.539$ moles of $HCl$

Now we have to calculate the mass of $HCl$ .

$\text{Mass of }HCl=\text{Moles of }HCl\times \text{Molar mass of }HCl$

$\text{Mass of }HCl=(1.539mole)\times (36.5g/mole)=56.1735g$

Therefore, the theoretical yield of HCl is, 56.1735 grams

7 0

3 years ago

Need help with question 1.) I got something wrong but i don’t know hurry ASAP

lana [24]

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2 years ago

An engineer uses aluminum to build an airplane rather than composite

lesantik [10]

Answer:

Explanation:

I would assume A because it says in the problem statement that chooses aluminum because he is worried that composite will suddenly fail... therefore he would use aluminum because it would bend before breaking and therefore show warning.

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3 years ago

Can unit rate represent how much for one unit

Ymorist [56]

Thank for you thank you please thank you sir I will have it for tomorrow morning and I have no problem getting you
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3 years ago

Read 2 more answers

What is the molality of a solution made by combining 5.0 g of CaCl2 with 500.0 g of water?

ankoles [38]

Molality is defined as the number of moles of solute dissolved in 1 kg of solvent.
To calculate molality, we need to calculate the number of moles of CaCl₂.
Mass of CaCl₂ - 5.0 g
Molar mass of CaCl₂ - 111 g/mol
The number of moles of CaCl₂ - 5.0 g / 111 g/mol = 0.045 mol
we need to then calculate the number of moles in 1 kg solvent.
number of CaCl₂ moles in 500 g water - 0.045 mol
Therefore number of moles in 1 kg water - 0.045 mol / 500g x 1000 g = 0.090 mol
Molality of CaCl₂ - 0.090 mol/kg

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3 years ago