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3 years ago

What is the approximate percent by mass of potassium in KHCO3?

Chemistry

1 answer:

lozanna [386]3 years ago

8 0

Answer:

The mass percent of potassium is 39%

Option C is correct

Explanation:

Step 1: Data given

Atomic mass of K = 39.10 g/mol

Atomic mass of H = 1.01 g/mol

Atomic mass of C = 12.01 g/mol

Atomic mass of O = 16.0 g/mol

Step 2: Calculate molar mass of KHCO3

Molar mass KHCO3 = 39.10 + 12.01 + 1.01 + 3*16.0

Molar mass KHCO3 = 100.12 g/mol

Step 3: Calculate mass percent of potassium (K)

%K = (atomic mass of K / molar mass of KHCO3) * 100%

%K = (39.10 / 100.12) * 100%

%K = 39.05 %

The mass percent of potassium is 39%

Option C is correct

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Which property is characteristic of ionic but not of covalent compounds? 1. low boiling point 2. non-conductor of electricity in

otez555 [7]

Ionic and covalent bonds are both strong intermolecular forces. They are generally both crystalline in structure. But relatively speaking, ionic bonds are much stronger. As a consequence, they have inherent properties of higher boiling points, higher melting points, lower volatility, etc. Also, ionic bonds display conductive properties because they are strong electrolytes. <em>Thus, the answer is 5) higher melting points.</em>

5 0

2 years ago

Caffeine has the molecular formula, C8H10N4O2. What is the percent composition of caffeine?

Debora [2.8K]

Answer:

b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O

Explanation:

we find the mass for each element in one mole by multiplying the number of atoms in one molecule with the atomic mass

mC=8Ac=8*12=96g

mH=10AH=10*1=10g

mN=4AN=4*14=56g

mO=2AO=2*16=32g

by adding the masses together we find the molar mass of the molecule

M=mC+nH+mN+mO=96+10+56+32=194g/mole

we apply the rule of threes to find the percentage of each element

194g..96gC..10gH...56gN....32gO

100g....a...........b...........c.............d

a=(100*96)/194=49.48%C

b=(100*10)/194=5.19%H

c=(100*56)/194=28.85%N

d=(100*32)/194=16.48%O

3 0

3 years ago

When calcium metal (Ca) reacts with oxygen gas (O2), it produces the ionic compound calcium oxide (CaO). Write the balanced equa

malfutka [58]

The balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

and

The process meets the requirements to be considered a redox reaction.

From the question,

We are to write a balanced chemical equation for the reaction between Calcium metal and oxygen gas

The balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

This is the balanced chemical equation for the reaction

To determine whether the reaction meets the requirements to be considered a redox reaction,

We will define the term <em>redox reaction</em>

A <em>redox reaction</em>, also called oxidation-reduction reaction, is any chemical reaction in which the oxidation number of a participating chemical species changes.

From the balanced equation above we can observe that the oxidation number of the participating species(Calcium and oxygen) changed.

The oxidation number of Calcium changed from 0 to +2

and

The oxidation number of Oxygen changed from 0 to -2

∴ The process meets the requirements to be considered a redox reaction.

Hence, the balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

and

The process meets the requirements to be considered a redox reaction.

Learn more here: brainly.com/question/17716543

7 0

2 years ago

For a phase change, H0 = 2 kJ/mol and A S0 = 0.017 kJ/(K•mol). What are

34kurt

Answer:

ΔG = -6.5kJ/mol at 500K

Explanation:

We can find ΔG of a reaction using ΔH, ΔS and absolute temperature with the equation:

ΔG = ΔH - TΔS

Computing the values in the problem:

ΔG = ?

ΔH = 2kJ/mol

T = 500K

And ΔS = 0.017kJ/(K•mol)

Replacing:

ΔG = 2kJ/mol - 500K*0.017kJ/(K•mol)

ΔG = 2kJ/mol - 8.5kJ/mol

8 0

2 years ago

can anyone help me with this and if my score is perfect i will brainlist u and follow you and please the answer must be the righ

mario62 [17]

Answer:

1.CL

2.SP

3.CL

4.SL

5.SL

6.SP

7.SL

8.CL

9.SL

10.CL

Explanation:

HOPE ITS HELP

5 0

2 years ago