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
Sedbober [7]
3 years ago
10

PLEASE HELP!!! PLEASE.

Chemistry
1 answer:
adell [148]3 years ago
6 0

Answer:

Q₁: [HCl] = 0.075 N = 0.075 M.

Q₂: [KOH] = 7.675 mN = 7.675 mM.

Q₃: [H₂SO₄] = 0.2115 N = 0.105 M.

Q₄:  The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.

Explanation:

<u><em>Q₁: If it takes 67 mL of 0.15 M NaOH to neutralize 134 mL of an HCl solution, what is the concentration of the HCl? </em></u>

  • As acid neutralizes the base, the no. of gram equivalent of the acid is equal to that of the base.
  • The normality of the NaOH and HCl = Their molarity.

<em>∵ (NV)NaOH = (NV)HCl</em>

<em>∴ N of HCl = (NV)NaOH / (V)HC</em>l = (0.15 N)(67 mL) / (134 mL) = 0.075 N.

∴ The concentration of HCl = 0.075 N = 0.075 M.

<u><em>Q₂: If it takes 27.4 mL of 0.050 M H₂SO₄ to neutralize 357 mL of KOH solution, what is the concentration of the KOH solution?</em></u>

  • As mentioned in Q1, the no. of gram equivalent of the acid is equal to that of the base at neutralization.
  • <em>The normality of H₂SO₄ = Molarity of H₂SO₄ x 2 = 0.050 M x 2 = 0.1 N.</em>

<em>∵  (NV)H₂SO₄ = (NV)KOH</em>

∴ N of KOH = (NV)H₂SO₄ / (V)KOH = (0.1 N)(27.4 mL) / (357 mL) = 7.675 x 10⁻³ N = 7.675 mN.

<em>∴ The concentration of KOH = 7.675 mN = 7.675 mM.</em>

<em></em>

<u><em>Q₃:If it takes 55 mL of 0.5 M NaOH solution to completely neutralize 130 mL of sulfuric acid solution (H₂SO₄), what is the concentration of the H₂SO₄ solution?</em></u>

  • As mentioned in Q1 and 2, the no. of gram equivalent of the acid is equal to that of the base at neutralization.

<em>The normality of NaOH = Molarity of NaOH = 0.5 N.</em>

<em>∵ (NV)H₂SO₄ = (NV)NaOH</em>

<em>∴ N of H₂SO₄ = (NV)NaOH / (V)H₂SO₄</em> = (0.5 N)(55 mL) / (130 mL) = 0.2115 N.

<em>∴ The concentration of H₂SO₄ = 0.2115 N = 0.105 M.</em>

<em></em>

<u><em>Q₄: Explain the difference between an endpoint and equivalence point in a titration.</em></u>

  • The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.
  • The equivalence point in a titration is the point at which the added titrant is chemically equivalent completely to the analyte in the sample. It comes before the end point. At the equivalence point, the millimoles of acid are chemically equivalent to the millimoles of base.
  • End point is the point where the indicator changes its color. It is the point of completion of the reaction between two solutions.
  • The effectiveness of the titration is measure by the close matching between equivalent point and the end point. pH of the indicator should match the pH at the equivalence to get the same equivalent point as the end point.
You might be interested in
Ultra Clorox bleach is 6.68% sodium hypochlorite in water. How much of each is needed to make an 800.mL bottle?
sweet-ann [11.9K]
If we have 6.68% NaClO, it is the same as saying--> 6.68 grams NaClO= 100 mL of solution. we can use this as a conversion. 

800. mL (6.68 mL/ 100 mL)= 53.4 mL

solution = solute + solvent

solute= NaClO
solvent= H2O

solvent= 800-53.4= 747 mL of H2O

so, we you need 53.4 mL of NaClO and 747 mL of water or 53.4 grams of NaClO and 747 mL of water
7 0
3 years ago
Name the parts of an electromagnet
Oxana [17]

Answer:

The iron core, copper wire, and an electricity source.

Explanation: Me

7 0
3 years ago
Water is a great solvent. For example, it causes ionic compounds like sodium chloride (table salt) to dissociate. One of these r
Ira Lisetskai [31]

Answer:

A polar molecule has both a partial positive and a partial negative. Since NaCl (sodium chloride) is made out of Na+ and Cl- ions, the positive and negative parts of the water will pull on these ions individually since positive attracts negative and negative attracts positive. This magnetic force causes the Na+ and the Cl- ions to be pulled apart.

Explanation:

5 0
3 years ago
Read 2 more answers
1) A toy car with a mass of 2.35 kg is pushed with a force of 21.6 N. What is the acceleration of the car?
Nataly_w [17]

Answer:

The acceleration of the car is 9,19 m/s2

Explanation:

We use the formula: F=m x a---> a=F/m

a=21,6N/ 2,35kg       1N is 1kgxm/s2

a=21,6 kg x m/s2 x 2,35 kg

a=9,191489362  m/s2

6 0
3 years ago
If 14.5 g of MnO4- (permanganate) react with manganese (II) hydroxide how many grams of manganese (IV) oxide will be produced? T
Veronika [31]

Answer:

m_{MnO_2}=21.2gMnO_2

Explanation:

Hello,

In this case, given the balanced reaction:

2MnO_4^-+2Mn(OH)_2\rightarrow 4MnO_2+2OH^-+H_2O

We can see a 2:4 mole ration between permanganate ion (118.9 g/mol) and manganese (IV) oxide (86.9 g/mol), that is why the resulting mas of this last one turns out:

m_{MnO_2}=14.5gMnO_4^-*\frac{1molMnO_4^-}{118.9gMnO_4^-}*\frac{4MnO_2}{2molMnO_4^-}  *\frac{86.9gMnO_2}{1molMnO_2} \\\\m_{MnO_2}=21.2gMnO_2

Best regards.

5 0
3 years ago
Other questions:
  • Select the correct answer.
    13·1 answer
  • Why do scientists measure and record mass instead of weight
    13·2 answers
  • How has the modern research in chemistry impacted society
    10·1 answer
  • How does the abundance of various isotopes affect the atomic mass?
    14·1 answer
  • What else is produced during the combustion of propane, C3H8?
    7·1 answer
  • How many moles of co2 are found in a 168.2 gram sample
    11·1 answer
  • Please please help
    12·1 answer
  • Minerals are formed by which process? O magma cooling O fault lines moving O metamorphosis O sedimentation​
    15·1 answer
  • The 4f subshell of an atom contains 14 electrons. What is the maximum number
    8·1 answer
  • In the laboratory you dissolve 22.0 g of nickel(II) nitrate in a volumetric flask and add water to a total volume of 125
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!