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julsineya [31]
3 years ago
14

What is the empirical formula? A compound being used in experimental medicine is 78.14% boron (B) and 21.86% hydrogen (H). The e

mpirical formula of the compound will have a boron to hydrogen ratio of :
Chemistry
1 answer:
Virty [35]3 years ago
3 0

The empirical formula is BH₃. Its B:H ratio is 1:3.

<em>Assume</em> that you have 100 g of the compound.

Then you have 78.14 g B and 21.86 g H.

Now, we must <em>convert these masses to moles</em> and <em>find their ratios</em>.

From here on, I like to summarize the calculations in a table.

<u>Element</u>  <u>Mass/g</u>    <u>Moles</u>     <u> </u><u>Ratio </u>     <u>Integers</u>

     B          78.14      7.2285    1                    1

     H          21.86    21.686      3.0001          3

The empirical formula is BH₃.

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In the explosion of a hydrogen-filled balloon, 0.60 g of hydrogen reacted with 4.8 g of oxygen. how many grams of water vapor ar
Kaylis [27]
First write the balanced equation of this reaction:
2H2 + O2 —> 2H2O

mol of H2= 0.60 gH2/2.02 gH2 = 0.297 mol
There are 2 mol of H2 for every 2 mol of H2O so the number of mol of H2 is equal to the number of mol of H2O.
g of H2O = 0.297 mol H2O • 18.02 gH2O = 5.35 g H2O

Do the same thing for O2:
mol of O2 = 4.8 gO2/32.0 gO2 = 0.15 mol of O2
There is 1 mol of O2 for every 2 mol of H2O so multiply 0.15 • 2 to get the number of mol of H2O
g of H2O = 0.30 mol H2O • 18.02 gH2O = 5.41 g H2O

The correct answer is 5.35 g H2O (or 5.4 g if checking significant figures) because O2, in this case, is the limiting reactant of this reaction.
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3 years ago
Heavy elements such as aluminum and carbon were formed by which of these phenomena? A. Big bang B. Fusion in very large star C.
Anton [14]
The answer is D. Supernova.

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3 years ago
A solid mixture consists of 47.6g of KNO3 (potassium nitrate) and 8.4g of K2SO4 (potassium sulfate). The mixture is added to 130
IgorLugansk [536]

<u>Answer:</u> No crystals of potassium sulfate will be seen at 0°C for the given amount.

<u>Explanation:</u>

We are given:

Mass of potassium nitrate = 47.6 g

Mass of potassium sulfate = 8.4 g

Mass of water = 130. g

Solubility of potassium sulfate in water at 0°C = 7.4 g/100 g

This means that 7.4 grams of potassium sulfate is soluble in 100 grams of water

Applying unitary method:

In 100 grams of water, the amount of potassium sulfate dissolved is 7.4 grams

So, in 130 grams of water, the amount of potassium sulfate dissolved will be \frac{7.4}{100}\times 130=9.62g

As, the soluble amount is greater than the given amount of potassium sulfate

This means that, all of potassium sulfate will be dissolved.

Hence, no crystals of potassium sulfate will be seen at 0°C for the given amount.

7 0
3 years ago
How did President Wilson anger civil rights advocates?
gogolik [260]

Answer:

He put segregationists in charge of federal agencies...

Explanation:

...

6 0
2 years ago
Read 2 more answers
In the following reaction 8 grams of ethane are burned and 11 grams of CO2 are collected. What is the percent yield? 2C2H6+7O2=
Alika [10]
47% yield.  
First, let's determine how many moles of ethane was used and how many moles of CO2 produced. Start with the respective atomic weights. 
Atomic weight carbon = 12.0107 
Atomic weight hydrogen = 1.00794 
Atomic weight oxygen = 15.999  
Molar mass C2H6 = 2 * 12.0107 + 6 * 1.00794 = 30.06904 g/mol 
Molar mass CO2 = 12.0107 + 2 * 15.999 = 44.0087 g/mol  
Moles C2H6 = 8 g / 30.06904 g/mol = 0.266054387 mol 
Moles CO2 = 11 g / 44.0087 g/mol = 0.249950578 mol  
Looking at the balanced equation, for every 2 moles of C2H6 consumed, 4 moles of CO2 should be produced. So at 100% yield, we should have 0.266054387 / 2 * 4 = 0.532108774 moles of CO2. But we only have 0.249950578 moles, or 0.249950578 / 0.532108774 = 0.46973587 =
46.973587% of what was expected.  
Rounding to 2 significant figures gives 47% yield.
8 0
4 years ago
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