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4 years ago

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The element sodium occurs naturally as a light solid with shiny metallic appearance. The diagram shows what will happen when a p

iece of pure sodium is placed in water. This indicates rat the properties of the element in the saw column on te periodic table as sodim have

1 answer:

Zepler [3.9K]4 years ago

4 0

Answer:

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Explanation:

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Please use the below balanced equation to answer this question. 2H2(g) + O2(g) -> 2H2O(l) How many grams of water wil

Blizzard [7]

At STP (standard temperature and pressure conditions), 1 mol of any gas occupies 22.4 L
This rule is applied to O₂
22.4 L volume occupied by 1 mol
Therefore 83.4 L occupied by - 1/ 22.4 x 83.4 = 3.72 mol
stoichiometry of O₂ to H₂O is 1:2
then the number of moles of water produced - 3.72 mol x 2= 7.44 mol
mass of water produced - 7.44 mol x 18.01 g/mol = 134.1 g
correct answer is D

4 0

3 years ago

Explain why the formation of sand is a physical change

iragen [17]

Answer:

Sand is still sand but if you were to change the feel of sand it would not be sand

Explanation:

5 0

3 years ago

Read 2 more answers

maks197457 [2]

<u>Answer:</u> The mass of $H_2O$ produced is 2.52 g

<u>Explanation:</u>

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

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

<u>For hexane:</u>

Given mass of hexane = 1.72 g

Molar mass of hexane = 86.18 g/mol

Putting values in equation 1, we get:

$\text{Moles of hexane}=\frac{1.72g}{86.18g/mol}=0.020mol$

<u>For oxygen gas:</u>

Given mass of oxygen gas = 8.0 g

Molar mass of oxygen gas= 32 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{8.0g}{32g/mol}=0.25mol$

The chemical equation for the combustion of hexane follows:

$2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O$

By stoichiometry of the reaction:

If 2 moles of hexane reacts with 19 moles of oxygen gas

So, 0.020 moles of hexane will react with = $\frac{19}{2}\times 0.020=0.19mol$ of oxygen gas

As the given amount of oxygen gas is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.

Thus, hexane is considered a limiting reagent because it limits the formation of the product.

By the stoichiometry of the reaction:

If 2 moles of hexane produces 14 moles of $H_2O$

So, 0.020 moles of hexane will produce = $\frac{14}{2}\times 0.020=0.14mol$ of $H_2O$

We know, molar mass of $H_2O$ = 18 g/mol

Putting values in above equation, we get:

$\text{Mass of }H_2O=(0.14mol\times 18g/mol)=2.52g$

Hence, the mass of $H_2O$ produced is 2.52 g

4 0

3 years ago

All elements have a ΔHf of 27314.1840 kJ/mole at standard temperature and pressure.

Naya [18.7K]

Answer: All elements have a ΔHf of 0 (zero) at standard temperature and pressure.

Standard ΔHf of formation is the standard enthalpy (heat) of formation of the compound. It is defined as the change of enthalpy when one mol of compound is formed in its standard state from the elements in their standard state.

Then, as the elements are already in their standard state, there is not any change and the standard enthalpy of an element in its standard state is, by definition, zero.

4 0

4 years ago

Gas A effuses 0.68 times faster than gas B. What is the molar mass of gas A if the molar mass of gas B is 17 grams?

ss7ja [257]

According to Graham's law of effusion, the ratio of the rates of effusion of two different molecules is equal to the square root of the reciprocal of the molar masses of the molecules. gas a is faster than B since it is lighter than B. Hence we expect a molar mass less than 17. we have the equation 1/0.68 = $\sqrt{ \frac{17}{x} }$ where x is the molar mass of gas A. This is equal to 7.86 grams.

5 0

4 years ago