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
laiz [17]
3 years ago
14

A 250.0 mL sample of aqueous solution contains an unknown amount of dissolved NaBr. Excess aqueous Pb(NO3)2is then added to this

solution and a precipitate forms.
A. If the mass of precipitate recovered was 3.006 grams, what was the molar concentration of Br–ions in the original solution?
B. What is the chemical formula of the precipitate?
C. Write the net ionic equation for this precipitation reaction.
Chemistry
1 answer:
Scrat [10]3 years ago
8 0

Answer:

A. 0.0655 mol/L.

B. PbBr2.

C. Pb2+(aq) + Br- --> PbBr2(s).

Explanation:

Balanced equation of the reaction:

Pb(NO3)2(aq) + 2NaBr(aq) --> PbBr2(s) + 2NaNO3(aq)

A.

Number of moles

PbBr2

Molar mass = 207 + (80*2)

= 367 g/mol.

Moles = mass/molar mass

= 3.006/367

= 0.00819 mol.

Since 2 moles of NaBr reacted to form 1 mole of PbBr2. Therefore, moles of NaBr = 2*0.00819

= 0.01638 moles of NaBr.

Since, the ionic equation is

NaBr(aq) --> Na+(aq) + Br-(aq)

Since 1 moles of NaBr dissociation in solution to give 1 mole of Br-

Therefore, molar concentration of Br-

= 0.0164/0.25 L

= 0.0655 mol/L.

B.

PbBr2

C.

Pb(NO3)2(aq)--> Pb2+(aq) + 2No3^2-(aq)

2NaBr(aq) --> 2Na+(aq) + 2Br-(aq)

Net ionic equation:

Pb2+(aq) + 2Br- --> PbBr2(s)

You might be interested in
BALANCE THIS EQUATION:<br> C4H10 + O2 = C02 + H20
Lostsunrise [7]

Answer:

{ \rm{C _{4} H_{10}+  \frac{13}{2} O _{2} = 4C0 _{2} + 5H _{2}0}} \\

5 0
3 years ago
What is the Ka value if pka=10.36
siniylev [52]
Pka = - log ka

10.36 = - log ka

Ka = .......
5 0
3 years ago
Read 2 more answers
3. Define isobar 75 points
steposvetlana [31]

Answer:

1.

meteorology A line drawn on a map or chart connecting places of equal or constant pressure.

2.

nuclear physics Either of two nuclides of different elements having the same mass number.

3.

thermodynamics A set of points or conditions at constant pressure.

5 0
3 years ago
Now that Snape and Dumbledore has taught you the finer points of hydration calculations they have a slightly more challenging pr
Mrrafil [7]

Answer:

The value of an integer x in the hydrate is 10.

Explanation:

Molarity=\frac{Moles}{Volume(L)}

Molarity of the solution = 0.0366 M

Volume of the solution = 5.00 L

Moles of hydrated sodium carbonate = n

0.0366 M=\frac{n}{5.00 L}

n=0.0366 M\times 5 mol=0.183 mol

Mass of hydrated sodium carbonate = n= 52.2 g

Molar mass of hydrated sodium carbonate = 106 g/mol+x18 g/mol

n=\frac{\text{mass of Compound}}{\text{molar mass of compound}}

0.183 mol=\frac{52.2 g}{106 g/mol+x\times 18 g/mol}

106 g/mol+x\times 18 g/mol=\frac{52.2 g}{0.183 mol}

Solving for x, we get:

x = 9.95 ≈ 10

The value of an integer x in the hydrate is 10.

6 0
3 years ago
29. Ammonia is formed with one nitrogen and three hydrogen atoms. What is the electron configuration of nitrogen? How
masya89 [10]

Answer:

<u>One lone-Pair is present in Ammonia</u>

<u></u>

Explanation:

The number of valence electron in N = 5

The number of Valence electron in H = 1

The formula of ammonia = NH3

Total valence electron in ammonia molecule = 5 +3(1) = 5+3 = 8

The lewis structure suggest that :

Nitrogen completes its octet by sharing the electron pair with 3 hydrogen atoms.

3 electron of Nitrogen are involved in sharing with Hydrogen

So,<u><em> remaining two electron are left non-bonded</em></u> . Hence they exist as lone- pair

So, there is only 1 lone pair in the ammonia molecule .

The shape of NH3 is bent according to VSEPR theory . This is so because the presence of 1 lone pair causes more repulsion and occupy more space.

Thus the lone pair is changing the shape of the ammonia molecule . It also increase the dipole moment of the molecule , which gives polarity to it.

5 0
3 years ago
Other questions:
  • The proper protective equipment for working with hazardous chemicals in the lab includes close lab coat goggles and a fume Hood
    15·1 answer
  • A sample of beach sand contains sand particles of different colors, small pebbles, and also shells. each component contains diff
    7·1 answer
  • He dissolution of gases in water is virtually always exothermic because __________. a gases react exothermically with water b th
    9·1 answer
  • Explain the ability of water to​
    13·1 answer
  • What is the definition of a covelant bond?
    7·1 answer
  • What is the pOH value when the solutions hydroxide concentration is 1.0 x 10−6 M?
    10·1 answer
  • Which event may occur when ocean salinity increases?
    12·2 answers
  • Explain why has a higher boiling point than NH3
    14·1 answer
  • When hydrogen is fused into helium, energy is released from
    12·1 answer
  • Suppose you found an unknown substance in a laboratory. It has the formula H2O2 written on the bottle. Is it water? How do you k
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!