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
Rufina [12.5K]
3 years ago
15

294 g of potassium dichromate contains 52 g of chromium and 39 g of potassium. What is the mass percent of oxygen in the compoun

d?
Chemistry
2 answers:
oee [108]3 years ago
7 0

The answer is 69.048%.


Mass of potassium dichromate (K₂Cr₂O₇) is 294 g, which is a 100%.


Given mass of chromium is 52 g. So, the mass percent of chromium in the compound is 17.687%:

52 g : x% = 294 g : 100%

x = 52 ÷ 294 × 100 %

x = 17.687%


Given mass of potassium is 39 g. So, the mass percent of potassium in the compound is 13.265%:

39 g : x% = 294 g : 100%

x = 39 ÷ 294 × 100 %

x = 13.265%


Therefore, the mass percent of oxygen in the compound is 69.048%:

100% - 17.687% - 13.265% = 69.048%.

IgorLugansk [536]3 years ago
3 0
69.047% is the answer to this question
You might be interested in
What is the molar mass of an unknown gas with a density of 2.00 g/L at 1.00 atm and 25.0 °C?
soldier1979 [14.2K]

Answer:

Explanation:Explanation:

Your starting point here will be the ideal gas law equation

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

P

V

=

n

R

T

a

a

∣

∣

−−−−−−−−−−−−−−−

, where

P

- the pressure of the gas

V

- the volume it occupies

n

- the number of moles of gas

R

- the universal gas constant, usually given as

0.0821

atm

⋅

L

mol

⋅

K

T

- the absolute temperature of the gas

Now, you will have to manipulate this equation in order to find a relationship between the density of the gas,

ρ

, under those conditions for pressure and temperature, and its molar mass,

M

M

.

You know that the molar mass of a substance tells you the mass of exactly one mole of that substance. This means that for a given mass

m

of this gas, you can express its molar mass as the ratio between

m

and

n

, the number of moles it contains

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

M

M

=

m

n

a

a

∣

∣

−−−−−−−−−−−−−

(

1

)

Similarly, the density of the substance tells you the mass of exactly one unit of volume of that substance.

This means that for the mass

m

of this gas, you can express its density as the ratio between

m

and the volume it occupies

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

ρ

=

m

V

a

a

∣

∣

−−−−−−−−−−−

(

2

)

Plug equation

(

1

)

into the ideal gas law equation to get

P

V

=

m

M

M

⋅

R

T

Rearrange to get

P

V

⋅

M

M

=

m

⋅

R

T

P

⋅

M

M

=

m

V

⋅

R

T

M

M

=

m

V

⋅

R

T

P

Finally, use equation

(

2

)

to write

M

M

=

ρ

⋅

R

T

P

Convert the temperature of the gas from degrees Celsius to Kelvin then plug in your values to find

M

M

=

1.02

g

L

⋅

0.0821

atm

⋅

L

mol

⋅

K

⋅

(

273.15

+

37

)

K

0.990

atm

M

M

=

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

26.3 g mol

−

1

a

a

∣

∣

−−−−−−−−−−−−−−−−

I'll leave the answer rounded to three

7 0
3 years ago
Classify each of these reactions. A single reaction may fit more than one classification. Ba ( ClO 3 ) 2 ⟶ BaCl 2 + 3 O 2 Ba(ClO
Lena [83]

Answer: a) Ba(ClO_3)_2\rightarrow BaCl_2+3O_2:  Decomposition

b) NaNO_2+HCl\rightarrow NaCl+HNO_2: double displacement

c) CaO+CO_2\rightarrow CaCO_3: Synthesis (Combination)

d) ZnSO_4+Mg\rightarrow MgSO_4+Zn: redox

Explanation:

Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.

Ba(ClO_3)_2\rightarrow BaCl_2+3O_2

A double displacement reaction is one in which exchange of ions take place.

NaNO_2+HCl\rightarrow NaCl+HNO_2

Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.

CaO+CO_2\rightarrow CaCO_3

Redox reaction is a type of chemical reaction in which oxidation and reduction takes place in one single reaction. The oxidation number of one element increases and the oxidation number of other element decreases.

ZnSO_4+Mg\rightarrow MgSO_4+Zn

4 0
3 years ago
If water was used to rinse the burette used to dispense the hydrochloric acid solution, how would this affect
Rufina [12.5K]

Answer:

The concentration of hydrochloric acid would be estimated to be less.

Explanation:

This is because, the hydroxyl ions from water react with the hydrogen ions from the hydrochloric acid, hence decreasing the moles of hydrogen ions which lowers the acidic strength of Hydrochloric acid.

7 0
3 years ago
An acid is used to bring the pH of a solution from pH 9 to pH 6. How many times more acidic is the final solution than the initi
Molodets [167]
Bleh bleh bleh bleh bleh bleh bleh bleh and bleh
5 0
2 years ago
Where was silk first discovered find out the answer<br>​
steposvetlana [31]

Answer:

China

Explanation:

The production of silk originates in China in the Neolithic (Yangshao culture, 4th millennium BC). Silk remained confined to China until the Silk Road opened at some point during the later half of the 1st millennium BC.

3 0
3 years ago
Other questions:
  • Determine the temperature of 2.49 moles of gas in a 1.0-L vessel at 143
    14·1 answer
  • During an experiment, solid iodine was placed in a sealed container. The container was gradually heated and purple-colored vapor
    9·2 answers
  • An atom of sodium has 11 protons, 11 electrons,and 12 neutrons, what is its atomic number and mass number?
    10·1 answer
  • during the combustion of methane one mole of methane gas combines with two moles of oxygen gas to produce one mole of carbon dio
    15·1 answer
  • How you could use the scientific method to learn whether water really does take longer to boil if you are watching it.
    11·1 answer
  • What does a low number on the pH scale say about a solution?
    5·2 answers
  • What is a gas quick!
    5·1 answer
  • Calculate the amount of heat associated with cooling a 350.0 g aluminum bar from 70.0 oC to 25.0 oC. The specific heat of alumin
    8·1 answer
  • Halppp can anyone come up with a slogan for anti smoking
    11·1 answer
  • 4. The nucleus of an atom is positively charged due to<br>A. electrons b. neutrons C. proton D. Ion​
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!