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3 years ago

Can someone help please

Chemistry

2 answers:

enyata [817]3 years ago

8 0

Answer:

d. cells are made of atoms and molecules. :)

Explanation:

hope i helped

Scrat [10]3 years ago

3 0

4th. Cells are made of atoms and molecules

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A certain box contains 200 particles of an ideal gas. how many times more likely is it to find the particles evenly split betwee

Strike441 [17]

Each particle has two possibilities: either it is on the left hand side or it is on the right hand side.

The probability of having them equally split is

P(100,100) = 200C100 / 2^200

where 200C100 is the binomial coefficient.

For the uneven distribution we have

P= 2 * 200C160 / 2^200

where the factor 2 comes in because we could have 160/40 or 40/160 as a division.

So the ratio of probabilities is

200C100 /(2 * 200C160 )

= 2.2 * 10^16

Hope this helps!

5 0

3 years ago

Consider the reaction 2Al(OH)3(s)→Al2O3(s)+3H2O(l) with enthalpy of reaction ΔHrxn∘=21.0kJ/mol What is the enthalpy of formation

bekas [8.4K]

Google knows your answer

8 0

3 years ago

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If a car travels 400.0 meters in 20.0 seconds, how fast is it going?<br> m/s<br> Please help me

Viefleur [7K]

Answer:

20m/s.

Explanation:

8 0

3 years ago

If 16.9 kg of Al2O3(s), 57.4 kg of NaOH(l), and 57.4 kg of HF(g) react completely, how many kilograms of cryolite will be produc

hodyreva [135]

Answer: 69.72 kg of cryolite will be produced.

Explanation:

The balanced chemical equation is:

$Al_2O_3(s)+6NaOH(l)+12HF(g)\rightarrow 2Na_3AlF_6+9H_2O$

To calculate the moles, we use the equation:

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

moles of $Al_2O_3$ = $\frac{16.9\times 1000g}{102g/mol}=165.7moles$

moles of $NaOH$ = $\frac{57.4\times 1000g}{40g/mol}=1435moles$

moles of $HF$ = $\frac{57.4\times 1000g}{20g/mol}=2870moles$

As 1 mole of $Al_2O_3$ reacts with 6 moles of $NaOH$

166 moles of $Al_2O_3$ reacts with = $\frac{6}{1}\times 166=996$ moles of $NaOH$

As 1 mole of $Al_2O_3$ reacts with 12 moles of $HF$

166 moles of $Al_2O_3$ reacts with = $\frac{12}{1}\times 166=1992$ moles of $HF$

Thus $Al_2O_3$ is the limiting reagent.

As 1 mole of $Al_2O_3$ produces = 2 moles of cryolite

166 moles of $Al_2O_3$ reacts with = $\frac{2}{1}\times 166=332$ moles of cryolite

Mass of cryolite $(Na_3AlF_6)$ = $moles\times {\text {molar mass}}=332mol\times 210g/mol=69720g=69.72kg$

Thus 69.72 kg of cryolite will be produced.

8 0

3 years ago

A lead sphere has a mass of 1.20 x 104 g, and its volume is 1.05 x 103 cm^3. Calculate the density of lead.

Hatshy [7]

Answer: The density of lead will be $11.42g/cm^3$

Explanation:

Density is defined as the mass contained per unit volume.

$Density=\frac{mass}{Volume}$

Given : Mass of lead= $1.20\times 10^4g$

Volume of lead = $1.05\times 10^3cm^3$

Putting in the values we get:

$Density=\frac{1.20\times 10^4}{1.05\times 10^3}=11.42g/cm^3$

Thus density of lead will be $11.42g/cm^3$

4 0

3 years ago