James has three cubes with identical dimensions. He places the blocks in water, as shown below.

How many sulfur atoms are there in 21.0 g of al2s3?

ValentinkaMS [17]

Given the mass of aluminum sulfide $Al_{2}S_{3}$ = 21.0 g

Molar mass of $Al_{2}S_{3}$ = $2 * Molar mass of Al + 3 *molar mass of S = 2(27g/mol)+3(32.g/mol)=150.g/mol$

Calculating the moles of $Al_{2}S_{3}$ :

$21.0 g *\frac{1 mol}{150 g} = 0.14 mol Al_{2}S_{3}$

Each mole $Al_{2}S_{3}$ has 3 mol S.

Each mole S constitutes $6.022*10^{23} atoms of S$

Calculating atoms of S in 0.14 mol $Al_{2}S_{3}$ :

$0.14 mol Al_{2}S_{3} *\frac{3mol S}{1 mol Al_{2}S_{3} }*\frac{6.022*10^{23}atoms S }{1 mol S}$

= $2.53 * 10^{23} atoms of S$

3 0

3 years ago

If 5.1 l of antifreeze solution (specific gravity = 0.80) is added to 3.8 l of water to make a 8.9 l mixture, what is the specif

Maslowich

Density of the mixture = mass of the mixture / volume of the mixture

Mass of the mixture = mass of antifreeze solution + mass of water.

Mass of antifreeze solution = density of the antifreeze solution * volume

Mass of antifreeze solution = 0.8g/ml * 5.1 l * 1000 ml / l = 4,080 g

Mass of water = density of water * volume of water = 1.0 g/ml * 3.8 l * 1000 ml / l = 3,800 g

Mass of mixture = 4080 g + 3800 g= 7880 g

Volume of mixture = volume of antifreeze solution + volume of water

Volume of mixture = 5100 ml + 3800 ml = 8900 ml

Density of mixture = 7800 g / 8900 ml = 0.876 g/ml

Specific gravity of the mixture = density of the mixture / density of water = 0.876

Answer: 0.876

3 0

3 years ago

For all the chemistry people out there. Explain why Benzene is more stable that 1,3,5-hexatriene? ...?

Triss [41]

Benzene is more stable because it contains a ring and therefore an aromatic compound. On the other hand, 1,3,5-hexatriene, as a straight-chain alkene, is aliphatic. Aromatic compounds in general are more stable than their aliphatic counterparts because pi electrons are part of a conjugated system, meaning they are "shared" amongst all double-bonded atoms.

4 0

3 years ago

A dog runs 68 meters from one corner of a rectangular park to the opposite corner . If the length of the park is 60 meters , wha

rewona [7]

Answer:

32 meters

Explanation:

You use the formula a^2 + b^2 = c^2.

Plug in the length and hypotenuse.

60^2 + b^2 = 68^2

Simplify and Solve:

3600 + b^2 = 4624

4624 - 3600 = b^2

1024 = b^2

Sqrt 1024 = 32

b = 32

6 0

3 years ago

Trimix 10/50 is a gas mixture that contians 10% oxygen and 50% helium, and the rest is nitrogen. If a tank of trimix 10/50 has a

Nataly_w [17]

Answer: 1.61 x 10⁴ kPa

Dalton's law states that the sum of the partial pressures of each gas equals the total pressure of the gas mixture. According to this law,

Pi = xi P

where Pi is the partial pressure of the gas i, xi is the mole fraction of the gas i in the gas mixture and P is the total pressure.

The mole fraction is defined as the quotient between the moles of solute (ni) and the total moles of the mixture (nt), which is calculated by adding the moles of all its components:

xi = $\frac{n_{i} }{n_{t} }$

In the Trimix 10/50 mix you have 10% oxygen, 50% helium and 40% nitrogen.

To calculate the total number of moles of the mixture and thus determine the molar fraction of helium, we consider 100 g and calculate the number of moles that represent 10 g of O₂ (n₁), 50 g of He (n₂) and 40 g of N₂ (n₃):

n₁ = 10 g x $\frac{1 mol}{31.998 g}$ = 0.313 mol