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3 years ago

Which statements accurately describe cells? Check all that apply.

Chemistry

2 answers:

shusha [124]3 years ago

5 0

Answer:

1,3 and, 4

Explanation:

Wewaii [24]3 years ago

3 0

Answer: 1, 3, and 4

Explanation: i just did it

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Given that the molar mass of carbon is 12 g/mol and the molar mass of oxygen is 16 g/mol, calculate the molar mass of carbon dio

nekit [7.7K]

Molar mass of oxygen is:
M(O)=16 g/mol
Molar mass of carbon is:
M(C)=12 g/mol
Molar mass of carbon dioxide is:
M(CO2)=M(C)+2*M(O)
M(CO2)=12 g/mol+2*16g/mol
M(CO2)=44 g/mol

Molar mass(M) is the mass of 1 mole of the substance (grams per mole of a compound).

7 0

3 years ago

an atmosphere is considered hazardous if it contains a hazardous gas in excess of 10 percent of the hazardous material's:

svlad2 [7]

Lower flammable limit means the lowest concentration of a material that will propagate a flame.

What is hazardous atmosphere?

It is an atmosphere that may expose employees to risk of death, incapacitation, impairment of ability to self-rescue, injury, or acute illness from one or more of following causes

Flammable gas, vapor, or mist in excess of 10 percent of lower flammable limit (LFL)
Airborne combustible dust at concentration that meets or exceeds its LFL

What is lower flammable limit?

It means the lowest concentration of a material that will propagate a flame.
The LFL is usually expressed as percent by volume of material in air (or other oxidant)
Atmospheres with concentration of flammable vapors at or above 10 percent of lower explosive limit (LEL) are considered hazardous when located in confined spaces.
However, atmospheres with flammable vapors below 10 percent of LEL are not necessarily safe. Such atmospheres are too lean to burn

Learn more about lower flammable limit at brainly.com/question/2456135

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6 0

1 year ago

Which best describes a molecule?

lesantik [10]

I think it is the third statement
‘A unit is made up of two or more atoms’

3 0

3 years ago

Read 2 more answers

Pls it’s urgent

Rainbow [258]

Answer:

0.02 moles.

Explanation:

volume of H₂ gas at R.T.P = 480 cm³

Where

R.T.P = room temperature and pressure

molar volume of gas at = 24000 cm³

no. of moles of hydrogen = ?

Solution:

formula Used

no. of moles = volume of gas / molar volume

put values in above equation

no. of moles = 480 cm³ / 24000 cm³/mol

no. of moles = 0.02 mol

So,

no. of moles of hydrogen in 480 cm³ is 0.02 moles.

4 0

3 years ago

A buffer contains 0.18 mol of propionic acid (C2H5COOH) and 0.26 mol of sodium propionate (C2H5COONa) in 1.20 L. What is the pH

Yuki888 [10]

Answer:

1) pH = 5.05

2) pH = 5.13

3) pH = 4.97

Explanation:

Step 1: Data given

Number of moles of propionic acid = 0.18 moles

Number of moles sodium propionate = 0.26 moles

Volume = 1.20 L

Ka = 1.3 * 10^-5 → pKa = 4.989

Step 2: Calculate concentrations

Concentration = moles / volume

[acid]= 0.18/ 1.2 =0.150 M

[salt]= 0.26/ 1.3 = 0.217 M

pH = 4.89 + log(0.217/0.150)=5.05

What is the pH of the buffer after the addition of 0.02 mol of NaOH?

moles acid = 0.18 - 0.02 = 0.16

[acid]= 0.16/ 1.2=0.133 M

moles salt = 0.26 + 0.02 = 0.28

[salt]= 0.28/ 12=0.233

pH = 4.89 + log 0.233/ 0.133 = 5.13

What is the pH of the buffer after the addition of 0.02 mol of HI?

moles acid = 0.18+ 0.02 = 0.20 moles

[acid]= 0.20/ 1.2 = 0.167 M

[salt]= 0.26 - 0.02= 0.24 moles

[salt]= 0.24/ 1.2 = 0.20 M

pH = 4.89 + log 0.20/ 0.167= 4.97

8 0

3 years ago