All categories

2 years ago

If 4.00 g of gallium is reacted with 5.50 g of arsenic how many grams of the excess reactant are left at the end of the reaction

2 answers:

8 0

<h2>The grams of the excess reactant that are left at the end of reaction is</h2><h2>= 1.2014 grams</h2>
<h3>calculation</h3>

find the moles of each reactant

moles = mass/molar mass

molar mass of Ga= 69.7 g/mol

molar mass of As= 74.9 g/mol

mole of Ga = 4 g÷69.7 g/mol=0.05739 moles

moles of As=5.50 g÷74.9 g/mol =0.07343 moles

0.05739 moles of Ga reacted completely with 0.05739 moles of As therefore As was in excess

Therefore the moles of As that did not react = 0.07343 - 0.05739=0.01604 moles

mass that did not react = moles that was left x molar mass of As

that is; 0.01604 x 74.9=1.2014 grams

Setler [38]2 years ago

8 0

Answer:

At the end of the reaction are left 1.20 g of excess reactant (arsenic).

Explanation:

1st) The first step to solve this problem is to write the chemical reaction between gallium and arsenic, which is as follow:

Ga + As → GaAs

The reaction is balanced and shows that 1 mol of gallium reacts with 1 mol of arsenic to produce 1 mol of gallium arsenide.

2nd) Now, to find the limiting and excess reactants we need to calculate the number of moles that are included in 4.00 g of gallium and 5.50 g of arsenic. So, let's look for the molar mass of each element in the periodic table:

Gallium molar mass: 69.72 g/mol

Arsenic molar mass: 74.92 g/mol

That means that 1 mol of gallium weights 69.72 g and 1 mol of arsenic weights 74.92 g.

So, if 1 mol of gallium weights 69.72 g, the 4.00 g that we have will weight "x" g. Let's solve this using the "Rule of three":

69.72 g -------------- 1 mol of gallium

4.00 g -------------- x = (4.00 g . 1mol)/69.72 g = 0.057 moles of gallium

With the same reasoning we can find the moles of arsenic:

74.92 g -------------- 1 mol of arsenic

5.50 g -------------- x = (5.50 g . 1mol)/74.92 g = 0.073 moles of arsenic

To find the limiting and excess reactants it is very important to follow what the chemical reaction shows.

- If 1 mol of gallium needs 1 mol of arsenic to react, the 0.057 moles of gallium that we have will need 0.057 moles of arsenic, and we have 0.073 moles of aersenic, so we have more arsenic that what we need, that means that <u>arsenic is the excess reactant</u>.

- We can do the same analysis with arsenic: if 1 mol of arsenic reacts with 1 mol of gallium, the 0.073 moles of arsenic will react with 0.073 moles of gallium, but we only have 0.057 moles of gallium, so <u>gallium is the limiting reactant</u>.

3rd) Once you find the limiting and excess reactants, you have make the following calculus based on the limiting reactant, because is the one that if it runs out, the reaction will stop.

Up to here, we know that there are 0.057 moles of gallium and 0.073 moles of arsenic, and that 1 mol of gallium reacts with 1 mol of arsenic, so the 0.057 moles of gallium will react with 0.057 moles of arsenic, and at the end of the reaction there will be 0.073 moles - 0.057 moles = 0.016 moles of arsenic.

And at the end of the reaction there will be 0 g of gallium (because it is the limiting reactant and it is all consumed in the reaction).

4th) Finally, find the grams of arsenic from the number of moles that are left. If 1 mol of arsenic weights 74.92 g, the 0.016 moles of arsenic that are left will weight "x" g. Let's use the Rule of three here:

1 mol of arsenic ------------ 74.92 g

0.016 moles of arsenic ------------ x = 1.20 g

Are left 1.20 g of arsenic (excess reactant).

You might be interested in

Two containers hold the same radioactive isotope. Container A contains 1000 atoms, and container B contains 500 atoms. which con

enyata [817]

Answer:

The rate of decay of atoms in container A is greater than the rate of decay of atoms in container B.

Explanation:

From the question,

Container A contains 1000 atoms

Container B contains 500 atoms

<u>The rate of decay of atoms in container A is greater than the rate of decay of atoms in container B.</u>

The reason for such is due to the difference in the concentration of the isotopes. Container A which contains higher number of atoms will have the more changes of the release of the neutron as the changes of the hitting and splitting increases as the density of the atoms increases.

<u>Thus, the atoms in the container A will therefore decay faster than the atoms in the container B. </u>

8 0

2 years ago

If the chemical reaction AB + CD ⟶ AD + BC releases heat, what is true of the stored bond energy of the reactants and products?

nignag [31]

Answer:

The correct option is the last option

Explanation:

The chemical reaction provided in the question is a double-displacement reaction which is an exothermic reaction (which is the reason for the release of heat). An example of a double displacement reaction and exothermic reaction is the neutralization reaction illustrated below.

HCl + NaOH ⇒ NaCl + H₂O

From the law of conservation of energy, energy can neither be created nor destroyed, hence the total energy in a given system should ordinarily be the same (in the reactants and products), however <u>when energy is released in a reaction (as in the case with an exothermic reaction), it shows there are more bond energy in the reactants than in the products and it is the excess energy that is been released into the atmosphere.</u>

3 0

2 years ago

Gizmo Student exploration feel the heat if a solute has really strong bonds between its particles , would you expect it to form

Troyanec [42]

Answer:

The temperature of the solute/solvent without any external effect would decrease.

Explanation:

As the bonding between the solute particles is really strong, therefore a large amount of energy is required to overcome these forces. So that the new bonding between the solute and solvent is created.

In order to achieve this, there will be a lot of energy required and that is through the heating process. So the solution will require energy so the solute will dissolve fully either by provision of external force i.e stirring or by heating.

4 0

2 years ago

A _____ change occurs when a substance changes phase. physical chemical nuclear user: the latent heat of vaporization of ethanol

dezoksy [38]

<span> physical

</span><span>about 200 calories of heat must be added to 1 gram of ethanol to convert it from a liquid to a gas</span><span>

</span>

3 0

2 years ago

Read 2 more answers

at 25c, 13.0 mg of co dissolves in 500g of water when the partial pressure of co is 0.968 bar. what is the henry's law constant

Olin [163]

Answer:

K = 9.59x10⁻⁴ m/bar

Explanation:

To do this, we need to write the Henry's law which is the following:

C = P*K (1)

K is the constant of the henry's law

C is the concentration of the solution

P is the pressure.

We have data for pressure which is 0.968 bar, and we need to calculate the concentration.

Concentration of any solution is calculated with the expression of molarity, which is:

C = n/V (2) m = n/kg water

The volume of this solution, will be the volume of water. Assuming density of water = 1 g/mL we can say that 500 g of water = 500 mL of water or 0.5 kg of water. But this is a solvent, so, we will calculate the molality instead of molarity

The moles are calculated with:

n = m/MM (3)

The molar mass of CO is:

MM CO = 12 + 16 = 28 g/mol

Now, let's use expression (3), (2) and finally the (1) to get the constant:

n = (13/1000) / 28 = 4.64x10⁻⁴ moles

Using expression (2), we will calculate the molality:

m = 4.64x10⁻⁴ / 0.5 = 9.28x10⁻⁴ m

Finally, from (1) we solve for K:

K = C/P

K = 9.28x10⁻⁴ / 0.968

K = 9.59x10⁻⁴ m/bar

8 0

2 years ago