1. Solid fossil fuel formed from _____________ remains. Produces energy when ____________

A sample of magnesium oxide has a mass of 94.4 g. How many molecules

ella [17]

Answer: 1.414x10^24 molecules in 94.4g MgO

Explanation: molar mass MgO 40.204

molecules in 40.204 g MgO = avogadro number

molecules in 94.4 g MgO = (94.4/40.204)*avogadro number

(94.4/40.204)*6.02214076*10^23 = 14.14x10^23

7 0

2 years ago

Sarah wants to find out how much time it would take to drive from her home to New York. At an average, she would drive at 55 mil

dimaraw [331]

The answer to your question is 13 hours/A

8 0

2 years ago

Read 2 more answers

The rock in a lead ore deposit contains 89 % PbS by mass. How many kilograms of the rock must be processed to obtain 1.5 kg of P

Zolol [24]

Answer:

Approximately 1.9 kilograms of this rock.

Explanation:

Relative atomic mass data from a modern periodic table:

Pb: 207.2;
S: 32.06.

To answer this question, start by finding the mass of Pb in each kilogram of this rock.

89% of the rock is $\rm PbS$ . There will be 890 grams of $\rm PbS$ in one kilogram of this rock.

Formula mass of $\rm PbS$ :

$M(\mathrm{PbS}) = 207.2 + 32.06 = 239.26\; g\cdot mol^{-1}$ .

How many moles of $\rm PbS$ formula units in that 890 grams of $\rm PbS$ ?

$\displaystyle n = \frac{m}{M} = \rm \frac{890}{239.26} = 3.71980\; mol$ .

There's one mole of $\rm Pb$ in each mole of $\rm PbS$ . There are thus $\rm 3.71980\; mol$ of $\rm Pb$ in one kilogram of this rock.

What will be the mass of that $\rm 3.71980\; mol$ of $\rm Pb$ ?

$m(\mathrm{Pb}) = n(\mathrm{Pb}) \cdot M(\mathrm{Pb}) = \rm 3.71980 \times 207.2 = 770.743\; g = 0.770743\; kg$ .

In other words, the $\rm PbS$ in 1 kilogram of this rock contains $\rm 0.770743\; kg$ of lead $\rm Pb$ .

How many kilograms of the rock will contain enough $\rm PbS$ to provide 1.5 kilogram of $\rm Pb$ ?

$\displaystyle \frac{1.5}{0.770743} \approx \rm 1.9\; kg$ .

5 0

3 years ago

PLZ HELP!!!!

Greeley [361]

In oil and gas industry:
When crude oil get extracted from well, salt water and some other stuff needs to be removed before oil can be sued in the car

6 0

3 years ago

6. The given mass of helium occupies

marin [14]

Answer:

V2 = 35.967cm^3

Explanation:

Given data:

P1 = 0.2atm

P2 = 1.4atm

V1 = 250cm^3

V2 = ?

T1 = 10°C + 273 = 283K

T2 = 12°C + 273 = 285K

Apply combined law:

P1xV1/T1 = P2xV2/T2 ...eq1

Substituting values:

0.2 x 250/283 = 1.4 x V2/285

Solve for V2:

V2 = 14250/396.2

V2 = 35.967cm^3

7 0

2 years ago

1. Solid fossil fuel formed from _____________ remains. Produces energy when _____________.

1. Solid fossil fuel formed from _ remains. Produces energy when _.