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4 years ago

What mass in grams of magnesium oxide is produced from 2.00 mol of magnesium?

Chemistry

1 answer:

Alexxx [7]4 years ago

5 0

Answer:

80 grams MgO(s)

Explanation:

2Mg(s) + O₂(g) => 2MgO(s); formula wt MgO = 40 g/mole

2moles Mg(s) gives 2moles MgO(s) => 2moles(40 g/mole) = 80 grams MgO(s)

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2 H2O2(aq)-> 2H20(l) + O2(g) ΔΗ -196 kJ/molrun The decompostion of H202(aq) is represented by the equation above. A student m

Aleks [24]

Answer:

the approximate pressure in the flask after 400. s = 1.2atm

Explanation:

The detailed explanation is shown below

5 0

3 years ago

A sample of 9.27 g9.27 g of solid calcium hydroxide is added to 38.5 mL38.5 mL of 0.500 M0.500 M aqueous hydrochloric acid. Writ

navik [9.2K]

Answer: The excess reagent for the given chemical reaction is calcium hydroxide and the amount left after the completion of reaction is 0.115375 moles. The amount of calcium chloride formed in the reaction is 1.068 grams.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ....(1)

For calcium hydroxide:

Given mass of calcium hydroxide = 9.27 g

Molar mass of calcium hydroxide = 74.093 g/mol

Putting values in above equation, we get:

$\text{Moles of calcium hydroxide}=\frac{9.27g}{74.093g/mol}=0.125mol$

To calculate the moles of a solute, we use the equation:

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

We are given:

Volume of hydrochloric acid = 38.5mL = 0.0385 L (Conversion factor: 1 L = 1000 mL)

Molarity of the solution = 0.500 moles/ L

Putting values in above equation, we get:

$0.500mol/L=\frac{\text{Moles of hydrochloric acid}}{0.0385L}\\\\\text{Moles of hydrochloric acid}=0.01925mol$

For the given chemical equation:

$2HCl(aq.)+Ca(OH)_2(s)\rightarrow CaCl_2(s)+2H_2O(l)$

Here, the solid salt is calcium chloride.

By Stoichiometry of the reaction:

2 moles of hydrochloric acid reacts with 1 mole of calcium hydroxide.

So, 0.01925 moles of hydrochloric acid will react with = $\frac{1}{2}\times 0.01925=0.009625moles$ of calcium hydroxide.

As, given amount of calcium hydroxide is more than the required amount. So, it is considered as an excess reagent.

Thus, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

Amount of excess reagent (calcium hydroxide) left = 0.125 - 0.01925 = 0.115375 moles

By Stoichiometry of the reaction:

2 moles of hydrochloric acid produces 1 mole of calcium chloride.

So, 0.01925 moles of hydrochloric acid will produce = $\frac{1}{2}\times 0.01925=0.009625moles$ of calcium chloride.

Now, calculating the mass of calcium chloride from equation 1, we get:

Molar mass of calcium chloride = 110.98 g/mol

Moles of calcium chloride = 0.009625 moles

Putting values in equation 1, we get:

$0.009625mol=\frac{\text{Mass of calcium chloride}}{110.98g/mol}\\\\\text{Mass of calcium chloride}=1.068g$

Hence, the excess reagent for the given chemical reaction is calcium hydroxide and the amount left after the completion of reaction is 0.115375 moles. The amount of calcium chloride formed in the reaction is 1.068 grams.

5 0

3 years ago

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How many minutes will it take for the quantity of n2o5 to drop to 1.9×10−2 mol ?

Novay_Z [31]

Missing question: The first-order rate constant for the decomposition of N2O5, 2N2O5(g)→4NO2(g) + O2(g) at 70°C is 6.82×10−3 s−1. Suppose we start with 2.70×10−2 mol of N2O5(g) in a volume of 1.8 L .
c₀(N₂O₅) = 0,027 mol ÷ 1,8 L.
c₀(N₂O₅) = 0,015 mol/L.
c(N₂O₅) = 0,019 mol/ 1,8 L = 0,01055 mol/L.
k = 6,82·10⁻³ s⁻¹.
ln c(N₂O₅) = ln c₀(N₂O₅) - k·t.
t = (ln c₀(N₂O₅) - ln c(N₂O₅)) ÷ k.
t = 0,35 ÷ 0,00682 s⁻¹.
t = 51 s = 0,86 min.

3 0

3 years ago

Given the following formula 2 KCIO3 -> 2 KCI + 3 O2 how many moles of O2 can be produced by letting 12 moles of KCIO3 react?

poizon [28]

1st you need to find the mole ratio between KClO3 and O2. To find that you need to take the coefficents of each of the compounds. That gives a ratio of 2:3.

Now we find out how many each unit is:
2x = 12
x = 6

Now we multiply it by 3 to find the number of moles of O2
3(6) = 18 mol O2.

6 0

3 years ago

Explain the Doppler effect using light. Why is the Doppler effect important in astronomy?

Alexeev081 [22]

Doppler effect is the compression or extension of a sound wave, which causes a change in its wavelength / frequency (and so its sound).
Explanation: It is defined as the effect produced by a moving source of waves in which there is an upward shift in frequency for observers, the source is moving towards and downward shift of frequency from which the source is moving away. used to tell if an object in space is moving toward or away from us.

8 0

4 years ago

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