What is the average speed of a skateboarder who travels 20 km in 2 hours

Paul [167]

Answer:

Soil provides nutrients, water, and minerals for plants and trees, stores carbon, and is home to billions of insects, small animals, bacteria, and many other microorganisms.

4 0

2 years ago

A 100 g sample of potassium chlorate, KCIO3(s), is completely decomposed by heating:

Mama L [17]

Explanation:
In order to be able to calculate the volume of oxygen gas produced by this reaction, you need to know the conditions for pressure and temperature.
Since no mention of those conditions was made, I'll assume that the reaction takes place at STP, Standard Temperature and Pressure.
STP conditions are defined as a pressure of
100 kPa
and a temperature of
0
∘
C
. Under these conditions for pressure and temperature, one mole of any ideal gas occupies
22.7 L
- this is known as the molar volume of a gas at STP.
So, in order to find the volume of oxygen gas at STP, you need to know how many moles of oxygen are produced by this reaction.
The balanced chemical equation for this decomposition reaction looks like this
2
KClO
3(s]
heat
×
−−−→
2
KCl
(s]
+
3
O
2(g]
↑
⏐
⏐
Notice that you have a
2
:
3
mole ratio between potassium chlorate and oxygen gas.
This tells you that the reaction will always produce
3
2
times more moles of oxygen gas than the number of moles of potassium chlorate that underwent decomposition.
Use potassium chlorate's molar mass to determine how many moles you have in that
231-g
sample
231
g
⋅
1 mole KClO
3
122.55
g
=
1.885 moles KClO
3
Use the aforementioned mole ratio to determine how many moles of oxygen would be produced from this many moles of potassium chlorate
1.885
moles KClO
3
⋅
3
moles O
2
2
moles KClO
3
=
2.8275 moles O
2
So, what volume would this many moles occupy at STP?
2.8275
moles
⋅
22.7 L
1
mol
=
64.2 L

6 0

3 years ago

Please help!!!!!! BRAINLIEST to right answer! :))

notsponge [240]

Explanation:

d. endothermic change as

heat is added to solid ice to change it to liquid water

6 0

3 years ago

How much money will it cost to drive a school bus 94.00 miles if it gets 6.500 miles per gallon and gas costs $2.459/gallon?

bagirrra123 [75]

Answer:

It will cost $35.5602

Explanation:

$2.459 /6.5 (mpg) = 0.3783 (cents per mile)

$0.3783 (cost per mile) * 94 (total miles) = $35.5602 total

6 0

1 year ago

Acetaminophen is the generic name of the pain reliever in Tylenol and some other headache remedies- The compoundhas the molecula

slega [8]

Answer: The mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %

Explanation:

We are given:

A chemical compound having chemical formula of $C_8H_9NO_2$ . This compound is made by the combination of carbon, hydrogen, nitrogen and oxygen elements.

1 mole of acetaminophen contains 8 moles of carbon atom, 9 moles of hydrogen atom, 1 mole of nitrogen atom and 2 moles of oxygen atom

Mass of carbon element = $(8\times 12)=96g/mol$

Mass of hydrogen element = $(9\times 1)=9g/mol$

Mass of nitrogen element = $(1\times 14)=14g/mol$

Mass of oxygen element = $(2\times 16)=32g/mol$

Mass of the compound = 151 g/mol

To calculate the percentage composition of an element in a compound, we use the equation:

$\%\text{ composition of an element}=\frac{\text{Mass of element}}{\text{Mass of compound}}\times 100$ ........(1)

For carbon element:

Putting values in equation 1, we get:

$\% \text{ composition of carbon element}=\frac{96}{151}\times 100\\\\\% \text{ composition of carbon element}=63.57\%$

For hydrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of hydrogen element}=\frac{9}{151}\times 100\\\\\% \text{ composition of hydrogen element}=5.96\%$

For nitrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of nitrogen element}=\frac{14}{151}\times 100\\\\\% \text{ composition of nitrogen element}=9.28\%$

For oxygen element:

Putting values in equation 1, we get:

$\% \text{ composition of oxygen element}=\frac{32}{151}\times 100\\\\\% \text{ composition of oxygen element}=21.19\%$

Hence, the mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %

6 0

3 years ago