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3 years ago

Janice ran a 5 km race on Saturday at 0.75 h. What was her speed? HELP MEHHH NOWWWW

Chemistry

2 answers:

a_sh-v [17]3 years ago

4 0

Speed=distance/time. S=5km/.75 h=6.67 kmh

ryzh [129]3 years ago

3 0

Answer

A runner ran 20 miles in 150 minutes. If she runs at that ... run in 15 minutes? How fast is she running in miles per hour? What is her pace in minutes per mile?

Explanation:

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⚠️HELP DUE IN 10 MINS WILL GIVE BRAINLIEST!!! THANKS⚠️

LenKa [72]

Answer:

hahahh noob

Explanation:

3 0

3 years ago

______ is a chemical property of matter.

Reika [66]

I think it’s chemical reactivity

4 0

3 years ago

My professor gave me two questions to solve using the Van Der Waals Equation. She told us to solve for P and the second one we h

Fed [463]

Answer:

P=atm

$b=\frac{L}{mol}$

Explanation:

The problem give you the Van Der Waals equation:

$(P+\frac{n^{2}a}{V^{2}})(V-nb)=nRT$

First we are going to solve for P:

$(P+\frac{n^{2}a}{V^{2}})=\frac{nRT}{(V-nb)}$

$P=\frac{nRT}{(V-nb)}-\frac{n^{2}a}{v^{2}}$

Then you should know all the units of each term of the equation, that is:

$P=atm$

$n=mol$

$R=\frac{L.atm}{mol.K}$

$a=atm\frac{L^{2}}{mol^{2}}$

$b=\frac{L}{mol}$

$T=K$

$V=L$

where atm=atmosphere, L=litters, K=kelvin

Now, you should replace the units in the equation for each value:

$P=\frac{(mol)(\frac{L.atm}{mol.K})(K)}{L-(mol)(\frac{L}{mol})}-\frac{(mol^{2})(\frac{atm.L^{2}}{mol^{2}})}{L^{2}}$

Then you should multiply and eliminate the same units which they are dividing each other (Please see the photo below), so you have:

$P=\frac{L.atm}{L-L}-atm$

Then operate the fraction subtraction:

P= $P=\frac{L.atm-L.atm}{L}$

$P=\frac{L.atm}{L}$

And finally you can find the answer:

P=atm

Now solving for b:

$(P+\frac{n^{2}a}{V^{2}})(V-nb)=nRT$

$(V-nb)=\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}$

$nb=V-\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}$

$b=\frac{V-\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}}{n}$

Replacing units:

$b=\frac{L-\frac{(mol).(\frac{L.atm}{mol.K}).K}{(atm+\frac{mol^{2}.\frac{atm.L^{2}}{mol^{2}}}{L^{2}})}}{mol}$

Multiplying and dividing units,(please see the second photo below), we have:

$b=\frac{L-\frac{L.atm}{atm}}{mol}$

$b=\frac{L-L}{mol}$

$b=\frac{L}{mol}$

7 0

3 years ago

Sylvanite is a mineral that contains 28.0% gold by mass. How much sylvanite would you need to dig up to obtain 73.0 g of gold?

Scorpion4ik [409]

You would have to dig up 261 g of sylvanite.

Mass of sylvanite = 73.0 g Au × (100 g sylvanite/28.0 g Au) = <em>261 g</em> sylvanite.

3 0

3 years ago

How many moles of carbon are in the sample?

mafiozo [28]

Answer:

12.01 grams per mole

Explanation:

theres no sample or example so if theres grams of Carbon, convert it to moles using 12.01g/mol

7 0

3 years ago