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
Diano4ka-milaya [45]
3 years ago
12

Percent composition. Please help meee :(

Chemistry
1 answer:
allsm [11]3 years ago
4 0

Answer:

Explanation:

Formula of percent composition:

% X = ( mass of element in compound / total mass of compound ) × 100

11) Al₂O₃

Al = 27 g/mol

O = 16 g/mol

%Al = (54 / 101.96) × 100

%Al = 52.9%

%O = (48 / 101.96) × 100

%O = 47.1%

12) C₅H₅O₅

C = 12 g/mol

H = 1 g/mol

O = 16 g/mol

C% = (60 / 145 ) × 100

C% =41.4%

H% = (5 / 145 ) × 100

H% =3.4%

O% = (80 / 145 ) × 100

O% = 55.2%

13) BaBr₂

Ba = 137.3 g/mol

Br =79.9 g/mol

Ba% = (137.3 / 297.14) × 100

Ba% = 46.2%

Br% = (159.8/ 297.14) × 100

Br% = 53.8%

14) Fe₃(PO₃)₂

Fe = 55.8 g/mol

P = 31 g/mol

O = 16 g/mol

Fe = (167.4/325.48)  × 100

Fe = 51.43%

P = (62/325.48)  × 100

P = 19.05%

O = (96 /325.48)  × 100

O = 29.49%

You might be interested in
Which property increases as you move down a column in the periodic table?
777dan777 [17]

Answer:

I think it's c have a good day

7 0
3 years ago
Read 2 more answers
It didn't have science but it is a science question. The average, year-after-year conditions of temperature, precipitation, wind
larisa86 [58]
Hey there,

Question : <span>The average, year-after-year conditions of temperature, precipitation, winds, and cloud in an area are known as its?

Answer : A, climate

Hope this helps :))

<em>~Top♥</em>
</span>
6 0
4 years ago
50 mL of 2.2 M HCl is combined with 50 mL of 2.0 M NaOH in a coffee-cup
GaryK [48]

Answer:

-56.1kJ/mol

Explanation:

The reaction between HCl and NaOH is:

NaOH + HCl → NaCl + H₂O + ΔH

<em>Where ΔH is heat change in  the reaction.</em>

<em />

As the temperature of the solution increases, the heat is released and ΔH < 0

The heat released in the reaction is obtained using coffe-cup calorimeter equation:

Q = C×m×ΔT

<em>Where Q is heat</em>

<em>C is specific heat of the solution (4.184J/g°C)</em>

<em>m is mass of solution: Assuming density = 1g/mL, 100mL of solution = 100g</em>

<em>And ΔT is change in temperature (13.4°C)</em>

<em />

Replacing:

Q = C×m×ΔT

Q = -4.184J/g°C×100g×13.4

Q = -5606.6J

Now, in the reaction you have:

<em>Moles HCl:</em>

0.050L * (2.2mol/L) = 0.11 moles

<em>Moles NaOH:</em>

0.050L * (2.0mol/L) = 0.1 moles

That means the moles of reaction are 0.1 moles, and heat change in the chemical reaction is:

5606.6J / 0.1 mol = 56066J =

<h3>-56.1kJ/mol</h3>

<em />

5 0
4 years ago
33. Which element in Period 5 of the Periodic Table
Sveta_85 [38]
B) Ag because it’s in the middle of the periodic table.
3 0
3 years ago
Read 2 more answers
The measured quantity 0.00410 g written in scientific notation is _______. Using prefixes, the number can be written as ________
vovangra [49]

Answer:

4.10x10⁻³g.

4.10 mg.

Explanation:

Hello,

In this case, considering the given number, we can see it has two digits after the first nonzero digit that is four (4) which is also at the third decimal place, it means that the scientific notation has a negative power as it is at the left of the given zeros, therefore it is:

4.10x10⁻³g.

Moreover, since the proper prefix for the factor x10⁻³ is milli, the number with prefix is:

4.10 mg.

Best regards.

6 0
3 years ago
Other questions:
  • Help me on number 4 and that last one says blood pressure
    10·1 answer
  • Balancing Chemical Equations.
    7·1 answer
  • 100 POINTS Which energy source produces electricity at a hydroelectric dam? A. solar panels B. wind turning turbines C. falling
    13·2 answers
  • PLEASE HELP ME I HAVE NO IDEA “Heat (thermal) energy is being applied to the substance whenever the Bunsen Burner is on. Before
    15·1 answer
  • Help me please thank you
    7·1 answer
  • A protein has the amino acid sequence
    15·1 answer
  • Which isotope has the greatest number of protons?
    6·1 answer
  • (i)Write two observations when lead nitrate is heated in a test tube.
    12·1 answer
  • What is the v if = 8 m and f = 20 Hz?
    6·1 answer
  • The liquid iodomethane has a density of 2.28 g/mL at 20.0°C. If a 109 gram sample of this compound is needed, what volume of the
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!