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
Naddik [55]
3 years ago
10

How many moles are there in 140.2 g of Ca

Chemistry
2 answers:
olga nikolaevna [1]3 years ago
7 0

Answer:

3.5

Explanation:

11111nata11111 [884]3 years ago
7 0
Ca molar mass = 40.078 g/mol

Therefore,

(40.078 g/mol)(1 mol/140.2 g) = 0.285 mol Ca
You might be interested in
Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin pla
RSB [31]

<u>Answer:</u> The enthalpy change of the reaction is -27. kJ/mol

<u>Explanation:</u>

To calculate the mass of water, we use the equation:

\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}

Density of water = 1 g/mL

Volume of water = 25.0 mL

Putting values in above equation, we get:

1g/mL=\frac{\text{Mass of water}}{25.0mL}\\\\\text{Mass of water}=(1g/mL\times 25.0mL)=25g

To calculate the heat released by the reaction, we use the equation:

q=mc\Delta T

where,

q = heat released

m = Total mass = [1.25 + 25] = 26.25 g

c = heat capacity of water = 4.18 J/g°C

\Delta T = change in temperature = T_2-T_1=(21.9-25.8)^oC=-3.9^oC

Putting values in above equation, we get:

q=26.25g\tiimes 4.18J/g^oC\times (-3.9^oC)=-427.9J=-0.428kJ

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

Given mass of ammonium nitrate = 1.25 g

Molar mass of ammonium nitrate = 80 g/mol

Putting values in above equation, we get:

\text{Moles of ammonium nitrate}=\frac{1.25g}{80g/mol}=0.0156mol

To calculate the enthalpy change of the reaction, we use the equation:

\Delta H_{rxn}=\frac{q}{n}

where,

q = amount of heat released = -0.428 kJ

n = number of moles = 0.0156 moles

\Delta H_{rxn} = enthalpy change of the reaction

Putting values in above equation, we get:

\Delta H_{rxn}=\frac{-0.428kJ}{0.0156mol}=-27.44kJ/mol

Hence, the enthalpy change of the reaction is -27. kJ/mol

4 0
3 years ago
Phenolphthalein is used as a visual indicator in a strong acid-strong base titration because
marysya [2.9K]
A strong acid- strong base titration is performed using a phenolphthalein indicator. Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. It will appear pink in basic solutions and clear in acidic solutions. ... It is known as the titrant.
3 0
3 years ago
How do u draw an electron dot diagram of an aluminum atom
xenn [34]

Answer:

you tell me

Explanation:

5 0
3 years ago
Read 2 more answers
126785033% Divided by 348675948849 = <br> what does it equal
meriva

Answer:

0.00000363618

could be wrong.

double check me someone or just trust me

(don't blame me if you get it wrong)

5 0
3 years ago
Which equation has x = 5 as the solution?
Natali5045456 [20]

Answer:

x-10 should be the answer

8 0
3 years ago
Other questions:
  • How many grams of CaF2 are present in 1.25 L of a 0.15 M solution of CaF2? How do I find the grams I am confused on that part?
    10·1 answer
  • If you changed the temperature of a ball from 28°C to 14°C, would you expect the pressure to increase or decrease?
    13·1 answer
  • Calculate the equilibrium constant for the reaction: 2 Cr + 3 Pb2+ ----&gt; 3 Pb + 2 Cr3+ at 25oC. Eocell = 0.61 V
    9·1 answer
  • Which planet contains high levels of carbon dioxide in its atmosphere resulting in a runaway greenhouse effect
    10·1 answer
  • Carbon bonding is almost entirely covalent. this property allows carbon compounds to _____. decompose easily, thereby providing
    13·1 answer
  • Determine the ph of a 0.227 m c5h5n solution at 25°c. the kb of c5h5n is 1.7 × 10-9.
    14·2 answers
  • the diagram below represents two beakers, each containing an ice cube and clear liquid. in beaker A the ice cube floats, and in
    13·1 answer
  • Which isotope has 45 neutrons?<br> O A. 80,36KT<br> OB. 80,35Br<br> O C. 78,345e<br> O D. 34,17C1
    12·1 answer
  • suppose that 9:00 am the temperature of a room is 18 ℃ , and at noon it is 24℃. WHat was the increase in temperature?
    7·1 answer
  • True or False:
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!