If a shell can hold a maximum of 32 electrons what is the value of n?

What is the mass in grams of 7.5 mol of C8H18?

Lana71 [14]

Answer:

$\boxed {\boxed {\sf 856.74 \ g \ C_8H _{18}}}$

Explanation:

To convert from grams to moles, the molar mass is used. These values tells us the grams in 1 mole of a substance. They can be found on the Periodic Table (they are equivalent to the atomic masses, but the units are grams per mole).

We are given the compound C₈H₁₈. Look up the molar masses of the individual elements.

Carbon (C): 12.011 g/mol
Hydrogen (H): 1.008 g/mol

Notice there are subscripts that tell us the number of atoms of each element. We must multiply the molar masses by the subscripts.

C₈: 8(12.011 g/mol)=96.088 g/mol
H₁₈: 18(1.008 g/mol)=18.144 g/mol

Add these 2 values together to find the molar mass of the whole compound.

C₈H₁₈: 96.088 g/mol +18.144 g/mol=114.232 g/mol

Use this number as a ratio.

$\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}$

Multiply by the given number of moles: 7.5

$7.5 \ mol \ C_8H_{18}*\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}$

The moles of C₈H₁₈ will cancel each other out.

$7.5 *\frac{ 114.232 \ g \ C_8H_{18}}{1}$

$7.5 *{ 114.232 \ g \ C_8H_{18}}$

$856.74 \ g \ C_8H _{18}$

7.5 moles of C₈H₁₈ is equal to <u>856.74 grams of C₈H₁₈</u>

8 0

2 years ago

. Calculate the molality of each of the following solutions: (a) 0.710 kg of sodium carbonate (washing soda), Na2CO3, in 10.0 kg

Step2247 [10]

Answer:

a)0.67 molal

b) 5.67 molal

c) 2.82 molal

d) 0.0268 molal

Explanation:

Step 1: Data given

Molality = moles solute / mass solvent

(a) 0.710 kg of sodium carbonate (washing soda), Na2CO3, in 10.0 kg of water—a saturated solution at 0°C

Calculate moles of Na2CO3 = 710 grams / 105.99 g/mol = 6.70 moles

Molality = 6.70 moles / 10 kg = 0.67 molal

(b) 125 g of NH4NO3 in 275 g of water—a mixture used to make an instant ice pack

Calculate moles of NH4NO3 = 125 grams / 80.04 g/mol = 1.56 moles

molality = 1.56 moles / 0.275 kg = 5.67 molal

(c) 25 g of Cl2 in 125 g of dichloromethane, CH2Cl2

Calculate moles Cl2 = 25 grams / 70.9 g/mol= 0.353 moles

Molality = 0.353 moles / 0.125 kg = 2.82 molal

0.372 g of histamine, C5H9N, in 125 g of chloroform, CHCl3

Calculate moles histamine = 0.372 grams / 111.15 g/moles = 0.00335 moles

Calculate molality = 0.00335 moles / 0.125 kg = 0.0268 molal

NOTE: histamine is C5H9N3 not C5H9N

4 0

3 years ago

How many nitrogen atoms are in 2.79 mo.of NH3

alexandr1967 [171]

1 mol of any particles has 6.02 * 10 ²³ particles.

If we look at 1 NH3 (1 mol NH3 or 1 molecule NH3), we can see that 1 molecule NH3 has 1 atom of N and 3 atoms of H; also 1 mole of NH3 has 1 mole of N atoms and 3 moles of H atoms.

So, 1 mol of NH3 has 1 mol of N atoms,
and 2.79 mol NH3 have 2.79 mol of N atoms.

2.79 mol of N atoms* 6.02 * 10 ²³ N atoms/ 1 mol N atoms = 1.68*10²⁴ N-atoms

Answer is 1.68*10²⁴ N-atoms.

5 0

3 years ago

Hi pls help pls pls. this is due at 11:59 help

Sveta_85 [38]

Answer:

mass of salt 6.72g

Explanation:

mass of the combine mass with salt- mass of the empty beaker

36.176g−29.456g=6.72g

7 0

1 year ago

A scientist observes how a particular South American bird cares for its young. Why is a field study an appropriate type of scien

mixer [17]

The best answer would be A. Hope i helped

7 0

2 years ago