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3 years ago

3. Which of the following substances is NOT an electrolyte? (1 point)

Chemistry

1 answer:

iren [92.7K]3 years ago

7 0

Answer: electrolytes hydrate you and give you energy.

Explanation: please add more information to this question. I can tell you this though from my answer it should help you define what is and isn't an electrolyte. I hope that this is helpful to you.

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Someone plz tell me this

Hatshy [7]

This. You welcome now can you plz give me thanks and brainly

3 0

3 years ago

Which of these is the percent of error in evaluating the molecular mass of a compound if the experimental value was 105.2 amu an

Bezzdna [24]

Answer:

The percent error, % error, is 2.1% (option f)

Explanation:

1) Data:

a) Experimental value, m₁ = 105.2 amu

b) Known value, m = 107.5 amu

b) % error = ?

2) Formulae:

a) absolute error = | experimental value - known value|

b) % error = [ absolute value / known value ] × 100

3) Solution:

a) absolute error = | m₁ - m | = | 105.2 amu - 107.5 amu | = 2.3 amu

b) % error = [ 2.3 amu / 107.5 amu ] × 100 = 2.1% ← answer

4 0

3 years ago

how many ml of 0.032 molar kmno4 are required to react with 50.0 ml of 0.100 molar h2c2o4 in the presence of excess h2so4

BartSMP [9]

Answer:

62.5 ml of 0.032 M KMnO₄ are required to react with 50.0 ml of 0.100 molar H₂C₂O₄ in the presence of excess H₂SO₄

Explanation:

The balanced reaction is:

2 KMnO₄ + 5 H₂C₂O₄ + 3 H₂SO₄ → K₂SO₄ + 2 MnSO₄ + 8 H₂O + 10 CO₂

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

KMnO₄: 2 moles
H₂C₂O₄: 5 moles
H₂SO₄: 3 moles
K₂SO₄: 1 mole
MnSO₄: 2 moles
H₂O: 8 moles
CO₂: 10 moles

Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

$Molarity=\frac{number of moles of solute}{volume}$

Molarity is expressed in units $\frac{moles}{liter}$

In this case, 50 mL (0.05 L) of 0.1 M H₂C₂O₄ react. So, replacing the data in the definition of molarity:

$0.1 M=\frac{number of moles of solute}{0.05 L}$

Solving:

number of moles of solute= 0.1 M*0.05 L

number of moles of solute= 0.005 moles

So, 0.005 moles of H₂C₂O₄ react. Then you can apply the following rule of three: if by stoichiometry 5 moles of H₂C₂O₄ react with 2 moles of KMnO₄, 0.005 moles of H₂C₂O₄ react with how many moles of KMnO₄?

$moles of KMnO_{4} =\frac{0.005moles of H_{2} C_{2} O_{4}* 2moles of KMnO_{4} }{5moles of H_{2} C_{2} O_{4} }$

moles of KMnO₄= 0.002 moles

Knowing that the molarity of KMnO₄ is 0.032 M, replacing in its definition and solving:

$0.032 M=\frac{0.002 moles}{volume}$

$volume=\frac{0.002 moles}{0.032 M}$

volume= 0.0625 L= 62.5 mL

62.5 ml of 0.032 M KMnO₄ are required to react with 50.0 ml of 0.100 molar H₂C₂O₄ in the presence of excess H₂SO₄

6 0

3 years ago

1. Using the Slater rule, determine the effective nuclear charge of platinum.

AleksandrR [38]

Answer:

Z* = 3.55

Explanation:

Slater rule says that:

Z*= Z - S

Z* be the nuclear effective charge

Z is the nuclear charge

S is the shielding constant

First we write the electronic configuration of platinum: $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{10} 5s^{2} 5p^{6} 4f^{14} 5d^{9} 6s^{1}$

The first Slater rule says that we need to group:

$(1s^{2}) (2s, 2p)^{8} (3s, 3p)^{8} (3d^{10}) (4s, 4p)^{8} (4d^{10}) (5s, 5p)^{8} (4f^{14}) (5d^{9}) (6s^{1})$

The second rule says that the electrons to the right are not shielding, but we are going to solve the exercise for the last level (6s), so we don't have electrons to the right.

For the third rule we have two considerations, if is ns or np and if is nd or nf:

For our case, we have an electro that is in ns, so the rule says that

-electrons within same group shield 0.35, except the 1s which shield 0.30

-electrons within the n-1 group shield 0.85

-electrons within the n-2 or lower groups shield 1.00

Now we can proceed with the calculation:

The first consideration in the third rule does not apply as we only have one electron on this level.

The second consideration will be as follow for the level 5, where we have 17 electrons.

Finally the third consideration will be for levels 1, 2, 3 and 4, where we have 14 for 4f, 10 for 4d, 8 for 4s and 4p, 10 for 3d, 8 for 3s and 3p, 8 for 2s and 2p and finally 2 for 1s, which gives 60 electrons.

So the result for S=(60*1.00 + 17*0.85) = 74.45

And the equation is: Z* = 78 - 74.45

So Z* = 3.55

3 0

3 years ago

Define physical change

STALIN [3.7K]

Answer to Question.

A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

4 0

4 years ago