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
Nataliya [291]
3 years ago
6

Suppose that 0.323 g of an unknown sulfate salt is dissolved in 50 mL of water. The solution is acidified with 6M HCl, heated, a

nd an excess of aqueous BaCl2 is slowly added to the mixture resulting in the formation of a white precipitate.
1. Assuming that 0.433 g of precipitate is recovered calculate the percent by mass of SO4 (2-) in the unknown salt.
2. If it is assumed that the salt is an alkali sulfate determine the identity of the alkali cation.
Chemistry
1 answer:
geniusboy [140]3 years ago
3 0

Answer:

1) 41.16 % = 0.182 grams

2) The alkali cation is K+ , to form the salt K2SO4

Explanation:

Step 1: Data given

Mass of unknown sulfate salt = 0.323 grams

Volume of water = 50 mL

Molarity of HCl = 6M

Step 2: The balanced equation

SO4^2- + BaCl2 → BaSO4 + 2Cl-

Step 3: Calculate amount of SO4^2- in BaSO4

The precipitate will be BaSO4

The amount of SO4^2- in BaSO4 = (Molar mass of SO4^2-/Molar mass BaSO4)*100 %

The amount of SO4^2- in BaSO4 = (96.06 /233.38) * 100

= 41.16%

So in 0.443g of BaSO4 there will be 0.443 * 41.16 % = <u>0.182 grams</u>

<u />

<u />

2. If it is assumed that the salt is an alkali sulfate determine the identity of the alkali cation.

The unknown sulphate salt has 0.182g of sulphate. This means the alkali cation has a weight of 0.323-0.182 = 0.141g grams

An alkali cation has a chargoe of +1; sulphate has a charge of -2

The formula will be X2SO4 (with X = the unknown alkali metal).

Calculate moles of sulphate

Moles sulphate = 0.182 grams (32.1 + 4*16)

Moles sulphate = 0.00189 moles

The moles of sulphate = 0.182/(32.1+16*4)

The moles of sulphate = 0.00189 moles

X2SO4 → 2X+ + SO4^2-

For 2 moles cation we have 1 mol anion

For 0.00189 moles anion, we have 2*0.00189 = 0.00378 moles cation

Calculate molar mass

Molar mass = mass / moles

Molar mass = 0.141 grams / 0.00378 grams

Molar mass = 37.3 g/mol

The closest alkali metal is potassium. (K2SO4 )

You might be interested in
NO<br> Assign oxidation numbers to each element in this compound.
marta [7]

Answer:

N=+2

O=-2

Explanation:

The compound NO is electrically neutral.

Lets assign the oxidation number of nitrogen to be N. The oxidation number of oxygen (-2) is then used as a reference.

For the compound to have a zero charge,  sum of the oxidation numbers equals zero.

N+ (-2)=0

N=+2

O=-2

7 0
3 years ago
How many moles of oxygen are necessary to completely react with propane (C3H8) to produce 16.3 mol of water according to the fol
velikii [3]
The balanced chemical reaction is expressed as:

<span>C3H8 + 5 O2 -> 3 CO2 + 4 H2O

We are given the amount of water produced. We use this amount for the calculations. We do as follows:

16.3 mol H2O ( 1 mol C3H8 / 4 mol H2O ) = 4.075 mol C3H8 needed

Hope this answers the question. Have a nice day.</span>
4 0
3 years ago
Read 2 more answers
It is necessary to know the time of day and the position of the Sun or the stars relative to one's longitude line because ____.
allochka39001 [22]

Answer: the longitude line rotates with Earth, 360 degrees in 24 hours.

Explanation: In the old days, the position of the sun was used to tell which time of the day it is. But more modern findings, has shown that the longitude line matters too.

3 0
3 years ago
Which of the solids in the following set should you test to investigate for the effects of ANIONS on pH? Will give brainliest
Alik [6]

Answer:

KCIO

Explanation:

the only reason is because I looked online and the meaning for that is potassium hypochlorite my guy so if this is not right then I'm sorry but good luck.

3 0
3 years ago
PLEASE HELP THIS IS DUE IN AN HOUR!!!
Soloha48 [4]

Explanation:

The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH) Example: What is the hydronium ion concentration in a solution that has a pH of 8.34? On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34).

7 0
3 years ago
Other questions:
  • 2.A fisherman in a boat is drinking hot coffee. The large lake below his boat is full of cold water. Which statement is an accur
    5·1 answer
  • What factor can limit the buffering capacity of a molecule?
    15·1 answer
  • What is the molar concentration (molarity) of a solution made by dissolving 0.285 moles of CaCl2(s) in just enough water to form
    10·1 answer
  • What will most likely happen if a sound wave moves from the air through a solid?
    15·2 answers
  • Identify the various types of fossil fuels helppp​
    5·1 answer
  • write the name of and molecular formula of compound which gives hydrogen ion and chloride ion in the solution state. in which co
    6·1 answer
  • GIVING BRAINLY, FOLLOW, 5 STARS AND HEARTS
    7·1 answer
  • Classically, if you put a particle in a box, it can have Zero kinetic energy (ie the particle is not moving). But a quantum part
    7·1 answer
  • Aqueous aluminum phosphate reacts with solid magnesium to produce solid aluminum and aqueous magnesium phosphate. Write the bala
    14·1 answer
  • Calculate the molecular mass of the element
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!