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
cluponka [151]
4 years ago
10

Please please help!

Chemistry
1 answer:
ratelena [41]4 years ago
3 0

 The mass  percent  of potassium chloride  is   1.386%

<u><em>calculation</em></u>

mass  percent = actual mass/ Theoretical mass x 100

Actual mass = 9.35 g

Theoretical mass  is  calculated as below

Step 1 : write the equation for reaction

KCl + H₂O  →   KOH + HCl

Step 2: find the moles of H₂O

moles = mass÷ molar mass

The molar mass of H₂O = (2 x1 ) +(16)  = 18 g/mol

moles is therefore = 162.98 g÷ 18 g/mol =9.054 moles

Step 3: use the mole ratio to determine the moles of KCl

KCl: H₂O  is 1:1 therefore the moles of KCl  is also = 9.054 moles

Step 4:  find the  theoretical mass of KCl

mass = moles x molar mass

from periodic table the  molar mass of KCl = 39 +35.5 =74.5 g/mol

mass = 9.054 moles x 74.5 g/mol =674.5 g


Theoretical mass is therefore = 9.35 g/ 674.5 g x 100 = 1.386%


You might be interested in
Calculate the pH of the solution that results when 20 mL of 0.2M HCOOH is mixed with 25mL of 0.2M NaOH solution.(post-equivalenc
Paul [167]

The pH of the solution : 12

<h3>Further explanation</h3>

Reaction

HCOOH    +     NaOH   ⇒     HCOONa   +   H₂O

mol HCOOH =

\tt 20~ml\times 0.2~M=4~mlmol

mol NaOH =

\tt 25~ml\times 0.2~M=5~mlmol

Mol NaOH>mol HCOOH ⇒ at the end of the reaction there will be a strong base remains from mol NaOH, so that the pH is determined from [OH⁻]

ICE method :

HCOOH    +     NaOH   ⇒     HCOONa   +   H₂O

4                          5

4                          4                     4                   4

0                          1                      1                    1

Concentration of [OH⁻] from NaOH :

\tt \dfrac{1~mlmol}{20+25~ml}=0.02

pOH=-log[OH⁻]

pOH=-log 10⁻²=2

pH+pOH=14

pH=14-2=12

3 0
3 years ago
Water alone does not easily remove grease from dishes or hands because grease is nonpolar and water is polar. The addition of so
rewona [7]

Answer:

Micelle Formation

Explanation:

The soap molecule has a nonpolar and a polar cationic end when it is dissolved in water. When it dissolves in water, the sodium stearate congregates to form small spheres (called micelles) with the on the inside and the on the surface. The anionic end can attract and interacts with the polar water molecules, while the interact with the nonpolar grease. This allows the soapy water to remove the grease by trapping the grease inside the micelle.

3 0
3 years ago
Etermine the percent yield of the following reaction when 2.80 g of P reacts with excess oxygen. The actual yield of this reacti
Elodia [21]

Answer:

Yield = 66.7%

Explanation:

4P + 5O₂ → 2P₂O₅

P: 31 g/mol

O₂: 32 g/mol

P₂O₅: 142 g/mol

31 g P ____ 1 mol

2.80 g P __     x

  x = 0.09 mol P

142 g P₂O₅ ____ 1 mol

3.89 g P₂O₅ ___     y

     y = 0.03 mol P₂O₅

In a 100% yield, 4 mol of P produces 2 mol of P₂O₅. 0.09 of P should, therefore, produce 0.045 mol of P₂O₅.

Yield = (0.03 mol / 0.045 mol) x 100

Yield = 66.7%

3 0
3 years ago
What is the science behind boncynes
maria [59]

Answer:

what.....?????

Explanation:

.......

5 0
3 years ago
1. Why<br> was sulfanilamide mixed with DEG, raspberry flavoring, and saccharine?
zzz [600]
Sulfanilamide, an antibacterial drug, was being used safely in the treatment of streptococcal infections.
3 0
3 years ago
Other questions:
  • In order for combustion to occur, what needs to happen?        A. A fuel sits in the presence of a small amount of oxygen.   B.
    13·2 answers
  • Can a "hot" ice cream mixture lose enough heat energy to ice to make ice cream freeze?
    12·1 answer
  • Methanol has the formula CH₃OH and can be produced by the reaction of carbon monoxide with hydrogen gas.
    5·1 answer
  • Please help me with this question!
    12·1 answer
  • A website promoting the use of alternative energy vehicles and hybrid technologies claims that, \"A typical automobile in the US
    8·1 answer
  • What type of reaction is nitrogen bromide?
    13·1 answer
  • Theoretical yield of Li2O​
    12·1 answer
  • How is pseudoscience different from non science
    12·1 answer
  • - A beam of electrons has.....
    14·1 answer
  • How do I solve the liters and grams in the mole calculations
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!