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3 years ago

If a sample of KF has a mass of 100.0 grams, how many moles of KF are present in the sample?

Chemistry

2 answers:

Mama L [17]3 years ago

8 0

Answer:

The answer to your question is the letter b. 1.721 moles

Explanation:

Data

mass of KF = 100 g

The Number of moles = ?

Process

1.- Calculate the Molar mass of KF using the periodic table

K = 39.1

F = 19

Molar mass = 39.1 + 19

= 58.1 g

2.- Calculate the number of moles of KF

58.1 g of KF ------------------- 1 mol

100 g of KF ------------------- x

x = (100 x 1) / 58.1

x = 100 / 58.1

x = 1.721 moles

DanielleElmas [232]3 years ago

3 0

Answer:

In a sample of 100.0 grams KF we have 1.721 moles of KF present (option B is correct)

Explanation:

Step 1: Data given

Mass of KF = 100.0 grams

Atomic mass of K= 39.10 g/mol

Atomic mass of F = 19.00 g/mol

Step 2: Calculate molar mass of KF

Molar mass KF = 39.10 + 19.00 = 58.10 g/mol

Step 3: Calculate moles of KF in the sample

Moles = mass / molar mass

Moles KF = 100.0 grams / 58.10 g/mol

Moles KF = 1.721 moles

In a sample of 100.0 grams KF we have 1.721 moles of KF present (option B is correct)

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Gennadij [26K]

Answer: The correct option is D. $Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu$

Explanation:

Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is known as the reaction in which the exchange of electrons takes place.

The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.

A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.

From the given ionic reactions:

$Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu$

On the reactant side:

Oxidation number of Zn = 0

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On the product side:

Oxidation number of Cu = 0

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As the oxidation number of Zn is increasing from 0 to +2. Thus, it is getting oxidized. Similarly, the oxidation number of Cu is decreasing from +2 to 0. Thus, it is getting reduced. Therefore, forming a redox couple

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2 years ago

What is photosynthesis?

tamaranim1 [39]

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3 years ago

If all the matter in the universe was birthed seconds after the Big Bang, then what was likely triggered the bang?

ArbitrLikvidat [17]

Answer:

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hope this helps

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3 years ago

Help on both please and thanks

Mamont248 [21]

Answer:

1. Granite

2. 535.5J

Explanation:

1. The lower the specific heat capacity of a substance, which is the amount of heat needed to raise the temperature of a particular mass of substance by 1 °C or K, the slower the rate at which the temperature is raised.

In this question 1, the substance with the lowest specific heat capacity in J/gK is GRANITE, hence, it will raise temperature the slowest.

2. Using the formula as follows:

Q = m × c × ∆T

Where;

c = specific heat capacity

Q = amount of heat (J)

m = mass of substance

∆T = change in temperature (°C)

m = 35g, c = 0.45 J/g°C, ∆T = 54°C - 20°C = 34°C

Q = 35 × 0.45 × 34

Q = 535.5J

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2 years ago

Unwanted elements are removed from metals by a process called

Grace [21]

Answer:

C. Refining

Explanation:

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2 years ago