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
madam [21]
2 years ago
7

Dissolve 30 g of sodium sulphate into 300 mL of water

Chemistry
1 answer:
Aneli [31]2 years ago
3 0

Answer:

number of moles = 0.21120811

Explanation:

To find the number of moles, given the mass of the solute, we use the formula:

\mathrm{n =   \dfrac{ m  }{ M  } }

\mathrm{n = number\:of\:moles\:(mol)}

\mathrm{m = mass\:of\:solute\:(g)}

\mathrm{M = molar\:mass\:of\:solute\:(  \dfrac{ g  }{ mol  }   )}

Label the variables with the numbers in the problem:

\mathrm{n =\:?}

\mathrm{m =30\:g }

\mathrm{M =\:?\:Calculate\:the\:molar\:mass }

The first thing we have to do is find the molar mass of sodium sulfate, in order for us to use the formula for finding the number of moles:

Formula for finding the molar mass of sodium sulfate:

M({ \left Na \right }_{ 2  }   { \left So \right }_{ 4  })   =  m \left( Na  \right)  +m \left( S  \right)  +m \left( O  \right)

For the variables and what they mean are below for finding the molar mass of sodium sulfate:

\mathrm{M =molar\:mass }

\mathrm{m =moles=2\:moles\:for\:Na\:,1\:mole\:for\:S,\:and\:4\:moles\:for\:O}

\mathrm{Na =sodium=22.99\:g }

\mathrm{S =sulfur=32.06\:g }

\mathrm{O =oxygen=16.00\:g }

Plug the numbers into the formula, to find the molar mass of sodium sulfate:

M({ \left Na \right }_{ 2  }   { \left So \right }_{ 4  })   =  m \left( Na  \right)  +m \left( S  \right)  +m \left( O  \right)

\mathrm{Substitute\:the\:values\:into\:the\:formula}

M  =  2 \left( 22.99  \right)  +1 \left( 32.06  \right)  +4 \left( 16.00  \right)

\mathrm{Multiply\:2\:by\:22.99\:to\:get\:45.98\:and\:1\:by\:32.06\:to\:get\:32.06}

\mathrm{M =  45.98+32.06+4\:(16)}

\mathrm{Multiply\:4\:by\:16\:to\:get\:64}

\mathrm{M =  45.98+32.06+64}

\mathrm{Add\:45.98\:and\:32.06\:to\:get\:78.04}

\mathrm{M =  78.04+64}

\mathrm{Add\:78.04\:and\:64\:to\:get\:142.04}

\mathrm{M =  142.04}

Now that we have found the molar mass, we can calculate the number of moles in the solution of sodium sulfate with the formula:

\mathrm{n =   \dfrac{ m  }{ M  } }

\mathrm{n =\:?}

\mathrm{m =30\:g }

\mathrm{M = 142.04\:g/mol}

\mathrm{Substitute\:the\:values\:into\:the\:formula}

\mathrm{n =   \dfrac{ 30  }{ 142.04  }}

\mathrm{Divide\:142.04\:by\:30\:to\:get\:0.21120811}

\mathrm{n =  0.21120811}

0.21120811 rounded gives you 0.2112

or if you did the problem without decimals

30 grams of sodium sulfate divided by its molecular weight – which we found to be 142 – gives us a value of 0.2113 moles.

You might be interested in
The atomic mass on the periodic table represents what?
Artyom0805 [142]
The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.

Atomic mass = Number of protons + number of neutrons

Hope this helps!
7 0
3 years ago
How are ironic bonds and covalent bonds different and how are they different?
Vinil7 [7]
Ionic bonds are forces that hold together electrostatic forces of attractions between oppositely charged ions. Ionic bonds have an electronegativity difference greater than or equal to 2. Covalent bonds have an electronegativity difference that is less than 2.
3 0
3 years ago
Measure of the average kinetic energy of molecules in an in an object
algol13
Yes because molecules is solid
8 0
2 years ago
Explain why is sodium less reactive than potassium
leva [86]

Answer:

As potassium is larger than sodium, potassium's valence electron is at a greater distance from the attractive nucleus and is so removed more easily than sodium's valence electron. As it is removed more easily, it requires less energy, and can be said to be more reactive.

Explanation:

<em>Hope you're having a splendiferous day</em><em>.</em>

<em>Just a bored kid willing to help...</em>

8 0
3 years ago
I need help with this chem study guide
Cloud [144]
Can you please provide a clearer image?
Thanks
7 0
3 years ago
Other questions:
  • You have a partially filled party balloon with 2.00 g of helium gas. you then add 2.74 g of hydrogen gas to the balloon. assumin
    8·1 answer
  • During which era did the supercontinent Pangaea break up?
    9·2 answers
  • How many grams of mgo are produced during an enthalpy change of -231 kj ?
    15·1 answer
  • How does a sample of helium at 15 degree Celsius compare to a sample of helium at 215 K?
    12·2 answers
  • Units used to measure the rate of electron flow
    6·1 answer
  • While washing his hands before the client consultation with Chloe, Jayden dropped some water onto the countertop. When he came b
    8·1 answer
  • Help please, 44 to 45, calculate the answers to the following problems. Use the following equation as the basis of your calculat
    10·2 answers
  • Calculate the value of K p for the equation C ( s ) + CO 2 ( g ) − ⇀ ↽ − 2 CO ( g ) K p = ? given that at a certain temperature
    9·1 answer
  • Which of the following describes a subalpine ecosystem?
    5·1 answer
  • A chemist reacted 57.50 grams of sodium metal with an excess amount of chlorine gas. The chemical reaction that occurred is show
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!