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3 years ago

Help please? :)

2 answers:

6 0

Increase the temperature (explained in the Collisions Theory) causes the particles to move faster (and so collide more frequently) and also have a higher energy so the collision is more likely to end in a reaction (as two particles must have a minimum energy in order to react).
Increasing the surface area increases the number of particles that can collide and so increases the rate of reaction.
The same is true with increasing pressure/ concentration.
Adding a catalyst lowers the energy required for a reaction to occur so increases the rate of reaction.

ivolga24 [154]3 years ago

4 0

Increasing the pressure will increase the reaction rate because it will force the particles to be closer together, and so the likelihood of particles colliding increases. Increasing the temperature can also increase the rate of a reaction because the particles will be more energised and more likely to move around and collide.

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How many electrons does an atom have if the atomic number is 11?

xenn [34]

There are 11 electrons

8 0

3 years ago

How much heat does a 100. g sample of copper absorb when its temperature increases by 30.0°C? The specific heat of copper is 0.3

erica [24]

Answer:

$\boxed {\boxed {\sf B. \ 1170 \ Joules }}$

Explanation:

We are asked to find how much heat a sample of copper absorbs when the temperature is increased.

Since we know the mass, temperature increase, and specific heat capacity, we can use the following formula to calculate heat.

$q= mc \Delta T$

The mass of the copper sample is 100 grams, the temperature is changed or increased by 30.0 degrees Celsius, and the specific heat of copper is 0.39 Joules per gram degrees Celsius.

m= 100 g
c= 0.39 J/g °C
ΔT= 30.0 °C

Substitute the values into the formula.

$q= (100 \ g )(0.39 \ J/g \textdegree C ) (30.0 \textdegree C )$

Multiply the first two values. Note that the units of grams cancel.

$q= 39 \ J/ \textdegree C (30.0 \textdegree C )$

Multiply again, this time the units of degrees Celsius cancel.

$q= 1170 \ J$

The copper sample absorbs 1170 Joules of heat and Choice B is correct.

7 0

3 years ago

If the initial [NO2] is 0.260 M, it will take ________ s for the concentration to drop to 0.150 M. If the initial is 0.260 , it

Nitella [24]

The question is incomplete, here is the complete question:

At elevated temperature, nitrogen dioxide decomposes to nitrogen oxide and oxygen gas

$NO_2\rightarrow NO+\frac{1}{2}O_2$

The reaction is second order for $NO_2$ with a rate constant of $0.543M^{-1}s^{-1}$ at 300°C. If the initial [NO₂] is 0.260 M, it will take ________ s for the concentration to drop to 0.150 M

a) 1.01 b) 5.19 c) 0.299 d) 0.0880 e) 3.34

Answer: The time taken is 5.19 seconds

Explanation:

The integrated rate law equation for second order reaction follows:

$k=\frac{1}{t}\left (\frac{1}{[A]}-\frac{1}{[A]_o}\right)$

where,

k = rate constant = $0.543M^{-1}s^{-1}$

t = time taken = ?

[A] = concentration of substance after time 't' = 0.150 M

$[A]_o$ = Initial concentration = 0.260 M

Putting values in above equation, we get:

$0.543=\frac{1}{t}\left (\frac{1}{(0.150)}-\frac{1}{(0.260)}\right)\\\\t=5.19s$

Hence, the time taken is 5.19 seconds

6 0

3 years ago

Fill in the blank.

labwork [276]

Answer:

Kinetic energy, Kelvin temperature, direction, warmer, cooler, Kelvin, Absolute zero

Explanation:

THe answers are in order and when there is a comma move to the next ______

7 0

2 years ago

The intensity of a sound describes

baherus [9]

The intensity of a sound describes its loudness at a particular distance

Sound intensity is factored by the ear's sensitivity to the particular frequencies contained in a sound

Sound loudness describes the strength of the ear's perception of a sound.

These two points being said, if the ear is more sensitive to a frequency, that sound will be louder to us than sounds at different frequencies that might not be as sensitive to our ears. So, the more intense the sound, the louder it is ;)

Thank you for your question! I hope this helped! Have an amazing day! :D

5 0

3 years ago