In class we r doing elements im doing gold and i need a surer hero name for gold it has to have gold in its name

Alex17521 [72]

We can get the mass of the lead metal by calculating the difference between the Mass of evaporating dish and lead metal and the mass of empty evaporating dish. The mass of lead metal is 1.9627 grams. The mass of sulfide is obtained by calculating the difference between Mass of evaporating dish and lead sulfide and the mass of evaporating dish and lead metal. The mass of sulfur added is 0.558 grams. We convert masses to moles. Lead is 0.0093 moles while sulfur is 0.017 moles. We divide each with the less amount between the two. Hence, lead is 1 an sulfur 1.83 or 2. The formula is PbS2 or lead (IV) sulfide.

4 0

3 years ago

Glycerol (C3H8O3), also called glycerine, is widely used in the food and pharmaceutical industries. Glycerol is polar and dissol

Stells [14]

Here is the complete question.

Glycerol (C3H8O3), also called glycerine, is widely used in the food and pharmaceutical industries. Glycerol is polar and dissolves readily in water and polar organic solvents like ethanol. Calculate the mole fraction of the solvent in a solution that contains 1.61 g glycerol dissolved in 22.60 mL ethanol (CH3CH2OH; density = 0.7893 g/mol). Round to four significant digits

Answer:

0.9567 mol

Explanation:

Given that:

mass of glycerol = 1.61 g

molar mass of glycerol = 92.1 g/mol

no of mole = $\frac{mass}{molar mass}$

∴ number of moles of glycerol ( $n_{glycerol}$ ) = $\frac{1.61}{92.1}$

= 0.0175 mol

Volume of ethanol = 22.60 mL

Density of ethanol = 0.7893 g/mL

Since Density = $\frac{mass}{volume}$

∴ mass of ethanol = density of ethanol × volume of ethanol

mass of ethanol = 0.7893 g/mL × 22.60 mL

mass of ethanol = 17.838 g

Number of moles of ethanol $(n_{ethanol})$ = $\frac{17.838}{46.0684}$

= 0.387 mole

∴ the mole fraction of the solvent can be determined as:

$X_{solvent} = X_{ethanol} =$ $\frac{n_{ethanol}}{n_{glycerol}+n_{ethanol}}$

$=\frac{0.387 mol}{(0.0175+0.387)mol}$

$= \frac{0.387mol}{0.4045mol}$

= 0.95673671199

≅ 0.9567 mol

∴ The mole fraction of the solvent in a solution that contains 1.61 g glycerol dissolved in 22.60 mL ethanol is = 0.9567 mol

7 0

3 years ago

How many moles of air must escape from a 10-m  8.0-m  5.0-m room when the temperature is raised from 0c to 20c? assume the p

slega [8]

Data:

p = 1 atm
V = 10 m * 8 m * 5 m = 400 m^3 = 400,000 liter

To = 0 + 273.15K = 273.15K
Tf = 20 + 273.15K = 293.15K

No - Nf =?

2) Formula

pV = NRT => N = pV / (RT)

3) solution

No = pV / (RTo)

Nf = pV / (RTf)

=> No - Nf = [pv / R] [ 1 / To - 1 / Tf ]

=> No - Nf = [1atm*400,000liter / 0.0821 atm*liter/K*mol ] [ 1 / 273.15 - 1 / 293.15]

No - Nf = 1216.9 moles ≈ 1217 moles

Answer: 1217 moles

3 0

2 years ago

Which substance has the highest ignition temperature?

erica [24]

It will be a. <span>benzene.</span>

7 0

3 years ago

What very specific property of mineral calcite allows geologists to quickly identify it in a mixture of other colorless minerals

iragen [17]

This is your perfect answer.

Other Identifying Characteristics
Calcite is easy to identify even without testing the reaction to HCl, by its hardness, luster and cleavage. Another special property is magnetism

3 0

2 years ago