1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
PIT_PIT [208]
3 years ago
6

Hydrofluoric acid solutions cannot be stored in glass containers because HF reacts readily with silica dioxide in glass to produ

ce hexafluorosilicic acid (H2SiF6).
SiO2(s) + 6 HF(aq) H2SiF6(aq) + 2 H2O(l)
21.0 g SiO2 and 70.5 g of HF react to yield 45.8 g H2SiF6.

(a) What is the limiting reactant?

HF
Or
SiO2



(b) What is the mass of the excess reactant?


g

(c) What is the theoretical yield of H2SiF6?


g

(d) What is the percent yield?

%
Chemistry
1 answer:
satela [25.4K]3 years ago
4 0
A) Limiting reactant

You need the molar ratios (from the balanced chemical equation) and the molar masses of each compound (from the atomic masses)

a) Molar ratios:

6 mol HF : 1 mol SiO2 : 1 mol H2SiF6

2) Molar masses:

Atomic masses:
H: 1 g/mol
F: 19 g/mol
Si: 28 g/mol
O: 16g/mol

=>
HF:1g/mol + 19 g/mol = 20 g/mol
SiO2: 28g/mol + 2*16g/mol = 60 g/mol
H2SiF6: 2*1g/mol + 28g/mol + 6*19g/mol = 144g/mol

3) convert data in grams to moles

21.0 g SiO2 / 60 g/mol = 0.35 mol SiO2

70.5 g HF /  20 g/mol = 3.525 mol HF

4) Use the theorical ratios to deduce which is in excess and which is the limiting reactant.

6 mol HF / 1mol SiO2   < 3.525 mol HF / 0.35 mol SiO2 ≈ 10

=> There is more HF than the needed to react with 0.35mol of SiO2 =>

SiO2 is the limiting reactant (HF is in excess)

b) Mass of excess reactant.

1) Calculate how many grams reacted, which requires to calculate first the number of moles that reacted

0.35 mol SiO2 * 6 mol HF / 1 mol SiO2 = 2.1 mol of HF

2.1 mol HF * 20 g/mol = 42 gram of HF

2) Subtract the quantity that reacted from the original quantity:

70.5 g - 42 g = 28.5 g of HF in excess

c) Theoretical yield of H2SiF6

1 mol of SiO2 ; 1 mol of H2SiF6 => 0.35 mol SiO2 : 0.35 mol H2SiF6

Convert those moles to grams: 0.35 mol * 144 g/mol = 50.4 grams

d) % yield

% yield = actual yield / theoretical yield * 100 = 45.8 / 50.4 * 100 = 90.87%
You might be interested in
Identify each of the following compounds as: (a) a nonelectrolyte: lactose (c12h22o11) potassium chloride (kcl) lactic acid (hc3
11Alexandr11 [23.1K]

Nonelectrolytes are compounds that do not tend to get ionize in all solution. As a result, solutions which contains nonelectrolytes will not conduct electricity.

Ionic compounds dissolve in water and break into the constituent ions through the process called ionization. Now These electrolyte solutions can either be acids, or bases, or salts.

If  the process of ionization produces a large no. of ions in the solution, it is a strong electrolyte. On the other hand, if it produces only a few ions, the solution is a weak electrolyte,

Potassium chloride (KCL) is a strong electrolyte,

Lactic acid (HC3H503) is a weak electrolyte,

Whereas, Ethanol (C3H7OH) is a non electrolyte,

Dimethylamine (CH3)2NH is a weak electrolyte,

Sodium hydroxide(NaOH) is a strong electrolyte.

To learn more about nonelectrolytes, head here

brainly.com/question/3712208

#SPJ4

6 0
1 year ago
What gives bases their properties?
svp [43]
Bases are iconic compounds that produce negative hydroxide ions (OH-) when dissolved in water. Bases taste bitter, feel slippery, and conduct electricity when dissolved in water.... Bases turn red litmus paper blue. The strength of bases is measured on the pH scale.
8 0
3 years ago
Water evaporating from a puddle is an example of a
Flauer [41]
It is an example of physical change. The molecules are not changing, so it is not chemical, and a physical property is something that a physical thing has.


5 0
3 years ago
Read 2 more answers
Noz at
Ne4ueva [31]

Answer:

<h2> ncjchchdgshdihdyshfjgjfjfjfjfjfjfjcjfjfjcn jivk kvi</h2>
4 0
3 years ago
What is the molarity of a solution prepared by dissolving 10.7 g NaI in 0.250 L?0.0714
hjlf

Answer:0.286M

Explanation:

10.7g / 149.89g/mol×0.25L

4 0
3 years ago
Read 2 more answers
Other questions:
  • What is a decay chain
    12·2 answers
  • The reaction described in part a required 3.35 l of calcium chloride. what is the concentration of this calcium chloride solutio
    10·1 answer
  • Which of the following will react violently with water to form a base?
    11·1 answer
  • Please help!!!!
    7·1 answer
  • Draw a highly magnified view of a sealed, rigid container filled with a gas. Then draw what it would look like if you cooled the
    5·1 answer
  • A 4.5x10 to the negative 3 M solution of a weak acid is 6.3% dissociated at 25%C. In a 4.5x10 to the negative 4 M solution, the
    13·1 answer
  • What human activities have change earth
    12·1 answer
  • Which statement is not true?
    7·1 answer
  • Which element is the most<br> reactive element in group one of the periodic<br> table
    12·1 answer
  • The characteristics of two different types of reactions are shown below: Reaction A: Electrons are gained by the atoms of an ele
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!