What would the formula be for this model above?

plez hurry Which is an important safety precaution that should be taken during a tornado? Stay away from doors and windows. Move

jeka57 [31]

Answer: stay away from doors and windows.

Explanation:

to aviod geting hit by glass

5 0

3 years ago

Read 2 more answers

What happens to the air as it gets farther from the heat source?

Effectus [21]

Answer:

molecules heat and move faster, they are moving apart. So air, like most other substances, expands when heated and contracts when cooled.

Explanation:

Because there is more space between the molecules, the air is less dense than the surrounding matter and the hot air floats upward.

6 0

3 years ago

Many computer chips are manufactured from silicon, which occurs in nature as SiO2. When SiO2 is heated to melting, it reacts wit

riadik2000 [5.3K]

Answer:

A) SiO2 is the limiting reactant

B) Theoretical yield= 72333.3g

C) % yield =91.5%

Explanation:

SiO2(s) + 2C(s) --------------> Si(s) + 2CO(g)

n(SiO2)= 155000/60 = 2583.33 mols

n(C)= 79000/12= 3291.66 mols

a)SiO2 is the limiting reactant

According to the balanced reaction equation,

60g of SiO2 produced 28g of SiO2

155000g of SiO2 will produce 155000×28/60= 72333.3g

Therefore theoretical yield of Si= 72333.3g

% yield= 66200/72333.3×100/1 =91.5%

5 0

4 years ago

For the reaction below, Kp 5 1.16 at 800.8C. CaCO3(s) 34 CaO(s) 1 CO2(g) If a 20.0-g sample of CaCO3 is put into a 10.0-L contai

Elena L [17]

Answer:

The mass percentage of calcium carbonated reacted is 2.5%.

Explanation:

The reaction is:

$CaCO_{3}(s)--->CaO(s)+CO_{2}(g)$

Thus the Kp of the equilibrium will be:

Kp = partial pressure of carbon dioxide [as the other are solid]

Moles of calcium carbonate initially present = $\frac{mass}{molarmass}=\frac{20}{100}=0.2$

Let us apply ICE table to the equilibrium given:

$CaCO_{3}(s)--->CaO(s)+CO_{2}(g)$

Initial 0.2 0 0

Change -x +x +x

Equilibrium 0.2-x x x

Kp = partial pressure of carbon dioxide

Kp = Kc(RT)ⁿ

where n = difference in the number of moles of gaseous products and reactants

for given reaction n = 1

R = gas constant = 8.314 J /mol K

T = temperature = 800 ⁰C = 1073 K

Putting values

Kc = $\frac{Kp}{RT}=\frac{1.16}{8.314X1073}=1.3X10^{-4}$

Kc = $\frac{[CO_{2}][CaO]}{[CaCO_{3}]}= \frac{x^{2} }{(0.2-x)}=1.3X10^{-4}$

$1.3X10^{-4}(0.2-x)=x^{2}$

$x^{2} = 0.26X10^{-4}-1.3X10^{-4}x$

On calculating

x = 0.005

where x = the moles of calcium carbonate dissociated or reacted.

Percentage of the moles or mass reacted = $\frac{molesreacted X100}{initialmoles}=\frac{0.005X100}{0.2}=2.5$ %

7 0

3 years ago

What is the yield of uranium from 2.50 kg U3O8?

mr_godi [17]

Answer: Thus the yield of uranium from 2.50 kg $U_3O_8$ is 2.12 kg

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number $(6.023\times 10^{23})$ of particles.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{molar mass}}$

moles of $U_3O_8=\frac{2.50\times 1000g}{842g/mol}=2.97mol$ (1kg=1000g)

As 1 mole of $U_3O_8$ contains = 3 moles of U

2.97 mole of $U_3O_8$ contains = $\frac{3}{1}\times 2.97=8.91moles$ moles of U

Mass of Uranium= $moles\times {\text {Molar mass}}=8.91mol\times 238g/mol=2120g=2.12kg$

( 1kg=1000g)

Thus the yield of uranium from 2.50 kg $U_3O_8$ is 2.12 kg

8 0

3 years ago