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Paladinen [302]

3 years ago

6

what is true of chemicals a- chemicals are never dangerous b- things containing chemicals cost alot of money c-chemicals are rar

ely found on earth d- chemicals are in many substances at home

1 answer:

Maslowich3 years ago

7 0

Answer: option d

Explanation:

Because every thing in our home is made from chemicals

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How can you measure the volume of air inside of a balloon?

Pani-rosa [81]

You could let the air out of the balloon while it is under the water with a container filled with water upside down over it. And measure the water displacement.

8 0

2 years ago

Students asked to measure the temperature of a reaction beaker recorded the following temperatures. 103.7°C, 108.4°C, 105.8°C, 1

Nata [24]

There are two terms

a) accuracy : it relates to the exactness of an answer that how an answer is close to the actual answer or actual reading

So 104.6 is accurate

b) Precision : This is related to the closeness of different readings with each other

The first reading is 103.7 and the second one is 108.4 so the second reading is quite different from the first reading so it cannot be called as precised

Again 105.8 has good difference from the second reading hence again this is not precised

However the last reading 104.6 is quite near to 105.8 so 104.6 can be called as precise

6 0

3 years ago

Read 2 more answers

Which of the following statements is true about gas particles?

satela [25.4K]

Answer:

There is a lot of empty space between them

Explanation:

We know that gas molecules are loosely packed,

Therefore there is a lot of intermolecular space...(Which basically means that there is a lot of space between the molecules or particles in a gas)

Happy to help.

Pls mark as Brainliest.

3 0

3 years ago

Read 2 more answers

Write a balanced half-reaction describing the reduction of aqueous vanadium(V) cations to aqueous vanadium(I) cations.

11Alexandr11 [23.1K]

Explanation:

Reduction is a chemical reaction in which electrons are gained by one of the atoms taking part in the reaction and lowering of an oxidation state of that atom.

Reduction takes place at the cathode.

In aqueous, vanadium(V) is present in +5 oxidation state which on reduction changes to vanadium(I) with +1 oxidation state.

The half reaction is :

$V^{5+}(aq)+4e^- \rightarrow V^{1+}(aq)$

5 0

2 years ago

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The half-life for the reaction below was determined to be 2.14 × 10^4 s at 800 K. The value of the half-life is independent of t

lord [1]

Answer:

0.0907 s

Explanation:

This an Arrhenius equation problem, so you relate the half-life with the kinetic constant of the reaction in order to calcule the same thermodynamic parameters at another temperature.

To calcule the kinetic constant of the reaction you need to know the order of it, look closely to the sentence "The value of the half-life is independent of the inital concentration of N2O present." the only order independent from the initial concentration of reagents is first order, so you can calculate K at 800 K, using:

$k(800 K)=\frac{ln(2)}{t_{1/2}}= \frac{ln(2)}{2.14 * 10^{4} s}}=3.239*10^{-5}s^{-1}}$

Now you can use Arrhenius equation to calcule K at 1150.66 K

$ln(\frac{k1}{k2} )=-\frac{E_{a} }{R}(\frac{1}{T2} - \frac{1}{T1} )$

$k2= k1*exp(-\frac{E_{a} }{R}(\frac{1}{T2} - \frac{1}{T1} ))=3.239*10^{-5}s^{-1}*exp(-\frac{270 000 J/mol }{8.314 J/mol *k }(\frac{1}{1150.66K} - \frac{1}{800K} ))=7.639 s^{-1}$

Then calculate the new half-life:

$t_{1/2} =\frac{ln(2)}{7.639s^{-1}}=0.0907 s$

3 0

3 years ago