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
alina1380 [7]
3 years ago
15

What mass (in grams) of Mg(NO3)2 is present in 151 mL of a 0.350 M solution of Mg(NO3)2?

Chemistry
2 answers:
Mademuasel [1]3 years ago
6 0

Answer is: A) 7.84 g.

V(Mg(NO₃)₂) = 151 mL ÷ 1000 mL/L.

V(Mg(NO₃)₂) = 0.151 L; volume of the magnesium nitrate.

c(Mg(NO₃)₂) = 0.352 M; molarity of the solution.

n(Mg(NO₃)₂) = V(Mg(NO₃)₂) · c(Mg(NO₃)₂).

n(Mg(NO₃)₂) ) = 0.151 L · 0.352 mol/L.

n(Mg(NO₃)₂) = 0.0531 mol; amount of the substance.

M(Mg(NO₃)₂) = Ar(Mg) + 2Ar(N) + 6Ar(O) · g/mol.

M(Mg(NO₃)₂) = 24.3 + 2·14 + 6·16 · g/mol.

M(Mg(NO₃)₂) = 148.3 g/mol; molar mass.

m(Mg(NO₃)₂) = n(Mg(NO₃)₂) · M(Mg(NO₃)₂).

m(Mg(NO₃)₂) = 0.0531 mol · 148.3 g/mol.

m(Mg(NO₃)₂) = 7.84; mass of magnesium nitrate.

kobusy [5.1K]3 years ago
3 0

The correct option is\boxed{{\mathbf{A}}{\mathbf{. 7}}{\mathbf{.84 g}}}.

Further explanation:

Mole is the S.I. unit. The number of moles is calculated as the ratio of mass of the compound to that of molar mass of the compound.

Molar mass also known as molecular weight is the sum of the total mass in grams of all the atoms that make up a mole of a particular molecule that is the mass of 1 mole of a compound. Its S.I unit is g/mol.

The expression to relate number of moles, mass and molar mass of compound is as follows:

{\text{Number of moles}}=\frac{{{\text{mass of the compound}}}}{{{\text{molar mass of the compound}}}}       …… (1)

Molarity:

The molarity is the concentration of the solution and is equal to the number of moles of the solute dissolved in liter of the solution.

The expression to relate molarity (M), volume (V), and the number of moles (n) is as follows:

{\text{M}}=\frac{{{\text{n}}\left({{\text{mol}}}\right)}}{{{\text{V}}\left({\text{L}}\right)}}                 …… (2)

Here, V is a volume of solution in liters and n is a number of moles of solute.

The conversion factor to convert volume in liter (L) to (mL) is written as follows:

{\text{1L}}=1000\;{\text{mL}}

Given volume of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}solution is 151 mL.

Therefore, 151 mL of volume is converted into (L) as follows:

\begin{aligned}{\text{Volume}}&=\,151{\text{ mL}}\left({\frac{{{\text{1}}\;{\text{L}}}}{{1000\;{\text{mL}}}}}\right)\\&=0.151{\text{ L}}\\\end{aligned}

On rearranging equation (2) for n, we get,

{\text{n(mol)}}={\text{M}}\times{\text{V(L)}}                   …… (3)

Concentration of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}} solution (M) is 0.350 M.

Volume of{\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}} solution is 0.151 L.

Substitute these values in equation (3) to calculate the number of moles (n).

\begin{aligned}{\text{n}}\left({{\text{mol}}}\right)&={\text{(0}}{\text{.350 M)}}\left( {\frac{{1\;{\text{mol/L}}}}{{{\text{1}}\;{\text{M}}}}}\right)\times\left({{\text{0}}{\text{.151 L}}}\right)\\&={\text{0}}{\text{.05285 mol}}\\\end{aligned}

The number of moles (n) of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}is 0.05285 mol.

The formula to calculate the mass of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}.

{\text{Mass of Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}={\text{moles of Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}\times {\text{molar mass of}}\;{\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}         …… (4)

Molar mass of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}is 148.3g/mol.

Moles of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}is 0.05285 mol.

Substitute these values in equation (4) to calculate the mass of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}.

\begin{aligned}{\text{Mass of Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}&=\left({{\text{0}}{\text{.05285}}\;{\text{mol}}}\right)\times\left({{\text{148}}{\text{.3}}\;{\text{g/mol}}}\right)\\&={\text{7}}{\text{.8376 g}}\\&\approx{\text{7}}{\text{.84 g}}\\\end{aligned}

Hence, 7.84 g of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}is present in 151 mL of 0.350 M of {\text{Mg(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}solution.

Learn more:

1. What is the concentration of acid brainly.com/question/6447527

2. Ranking of photons according to the wavelength of transition: brainly.com/question/2055545

Answer details:

Grade: SeniorSchool

Subject: Chemistry

Chapter: Solutions

Keywords: mole, molarity, volume, concentration, 151 mL,0.350M, 0.05285 mol, 148.3g/mol.

You might be interested in
What is the velocity of a plane that traveled 3000 miles from New York to Los Angeles in 5.0 hours?
miss Akunina [59]

Answer:

600 mph

Explanation:

Just divide 3000 by 5.

3 0
3 years ago
What happens to the rate of dissolution as the temperature is increased in a gas solution?
Nina [5.8K]

Answer:

The rate decreases

Explanation:

When we dissolve a gas in a water, the process is exothermic. This implies that heat is evolved upon dissolution of a gas in water.

Recall from Le Chateliers principle that for exothermic reactions, an increase in temperature favours the reverse reaction. The implication of these is that when the temperature of the gas is increased, less gas will dissolve in water.

Hence increase in temperature decreases the rate of solubility of a gas in water.

8 0
3 years ago
Be sure to answer all parts. Calculate the molality, molarity, and mole fraction of FeCl3 in a 24.0 mass % aqueous solution (d =
Anna71 [15]

Answer:

m= 1.84 m

M= 1.79 M

mole fraction (X) =

Xsolute= 0.032

Xsolvent = 0.967

Explanation:

1. Find the grams of FeCl3 in the solution: when we have a mass % we assume that there is 100 g of solution so 24% means 24 g of FeCl3 in the solution. The rest 76 g are water.

2. For molality we have the formula m= moles of solute / Kg solvent

so first we pass the grams of FeCl3 to moles of FeCl3:

24 g of FeCl3x(1 mol FeCl3/162.2 g FeCl3) = 0.14 moles FeCl3

If we had 76 g of water we convert it to Kg:

76 g water x(1 Kg of water/1000 g of water) = 0.076 Kg of water

now we divide m = 0.14 moles FeCl3/0.076 Kg of water

m= 1.84 m

3. For molarity we have the formula M= moles of solute /L of solution

the moles we already have 0.14 moles FeCl3

the (L) of solution we need to use the density of the solution to find the volume value. For this purpose we have: 100 g of solution and the density d= 1.280 g/mL

The density formula is d = (m) mass/(V) volume if we clear the unknown value that is the volume we have that (V) volume = m/d

so V = 100 g / 1.280 g/mL = 78.12 mL = 0.078 L

We replace the values in the M formula

M= 0.14 moles of FeCl3/0.078 L

M= 1.79 M

3. Finally the mole fraction (x)  has the formula

X(solute) = moles of solute /moles of solution

X(solvent) moles of solvent /moles of solution

X(solute) + X(solvent) = 1

we need to find the moles of the solvent and we add the moles of the solute like this we have the moles of the solution:

76 g of water x(1 mol of water /18 g of water) = 4.2 moles of water

moles of solution = 0.14 moles of FeCl3 + 4.2 moles of water = 4.34 moles of solution

X(solute) = 0.14 moles of FeCl3/4.34 moles of solution = 0.032

1 - X(solute) = 1 - 0.032 = 0.967

6 0
3 years ago
4P+ 5O2 -> P4O10
Ratling [72]
If 4 moles of P is used by 5 mole of O2
then....0.489 moles will be used by 5/4 × .489 = .611 moles of O2

so .611 moles

so if 4 moles of P is burnt , 1 mole of P4O10 is produced ....so for .489 moles...... .489/4=.122 moles !
so mass will be .122× 283.89 = 34.7 grams

so first ans is .611 moles and second is 34.7 grams !

if you have any problem regarding this , just comment !!!
4 0
3 years ago
Read 2 more answers
(I will give brainliest, ONLY if its correct!)
ryzh [129]

Answer:

easy

Explanation:

In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.

7 0
3 years ago
Read 2 more answers
Other questions:
  • Jim collects a sample of beach sand during a class trip. After a close inspection of the sample he classifies it as a __________
    5·2 answers
  • How long can carbon dioxide remain in the environment after it is released?
    6·2 answers
  • Whatcha energy transfer occurs when a student blows a whistle? The top one
    10·2 answers
  • Is it possible to distinguish kc from kp by comparing the units used to express the equilibrium constnat?
    7·1 answer
  • The chemical symbol for sodium is<br> A. N.<br> B. S.<br> C. Na.<br> D. Sn.
    5·2 answers
  • Do yeast need air to release carbon dioxide?
    14·1 answer
  • Convert the following pressures to pressure in standard atmosphere 151.98 kPa 456 torr
    11·1 answer
  • How does conc.H2SO4 reacts with sugar?​
    8·1 answer
  • Which of the following most likely happens when the number of particles of a gas decreases?
    6·1 answer
  • As the frequency of a wave increases, what happens to the energy the wave is carrying?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!