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3 years ago

How do you analyze chemical evidence?

1 answer:

3 0

BIOLOGICAL & CHEMICAL EVIDENCE ANALYSIS
There are many different types of evidence that can be found at a crime scene. Physical evidence can be collected at the crime scene such as a murder weapon. Chemical evidence is any residue from liquids that such as poison and drugs. Biological evidence is when hair or skin from a persons body has been transferred to a physical surface and then be collected and tested.

This evidence can be used to find out what exactly happened at the scene of the crime, the history behind the crime and who was involved and could have committed it.

Our experts test and analyse many forms of evidence, which is vital when finding out the various incidences that happened at a crime scene.

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In order for a process to be spontaneous, Multiple Choice the entropy of the surroundings must increase. the entropy of the surr

Crazy boy [7]

Answer:

The correct answer is entropy change of the surrounding plus the entropy change of the system must be positive.

Explanation:

The term entropy is a state function.Entropy can be defined as the disorder or randomness of the molecules in a system.

A spontaneous reaction is a type of reaction which deals with the release of free energy.The change of free energy in case of spontaneous reaction is always negative.

According to the second law of thermodynamics a spontaneous reaction will occur in a system if the total entropy of both system and surrounding increases during the reaction.

8 0

3 years ago

Carbonyl fluoride, COF2, is an important intermediate used in the production of fluorine-containing compounds. For instance, it

lions [1.4K]

Answer: The equilibrium concentration of $COF_2$ is 0.332 M

Explanation:

We are given:

Initial concentration of $COF_2$ = 2.00 M

The given chemical equation follows:

$2COF_2(g)\rightleftharpoons CO_2(g)+CF_4(g)$

Initial: 2.00

At eqllm: 2.00-2x x x

The expression of $K_c$ for above equation follows:

$K_c=\frac{[CO_2][CF_4]}{[COF_2]^2}$

We are given:

$K_c=6.30$

Putting values in above expression, we get:

$6.30=\frac{x\times x}{(2.00-2x)^2}\\\\x=0.834,1.25$

Neglecting the value of x = 1.25 because equilibrium concentration of the reactant will becomes negative, which is not possible

So, equilibrium concentration of $COF_2=(2.00-2x)=[2.00-(2\times 0.834)]=0.332M$

Hence, the equilibrium concentration of $COF_2$ is 0.332 M

4 0

3 years ago

Should we only write condensed formula in chemical equations (for lessons like carbon and compounds). What did your teachers say

Firlakuza [10]

Answer:

Here's what I get.

Explanation:

If your teachers don't ask for a specific type of formula, a condensed structural formula should be OK.
If they ask specifically for a structural formula or a bond-line formula, that is what you must give.

Bottom line: ask your teachers in advance what they expect.

7 0

3 years ago

Which is heavier? 30kg or 60lb?

Maurinko [17]

30kg think of it like this imagine you are moving to your college dorm would you have you carry the box if weights or will you carry your books instead

4 0

3 years ago

What is the actual amount of phosphorous in a fertilizer with a npk ratio of 15-15-20?

OLga [1]

NPK ratio system is a conventional shorthand for the ratio of the nitrogen N), phosphorus (P) and potassium (K) in a fertilizer. It actually shows amount of P₂O₅.
If we use 100 kg of P₂O₅:
m(P₂O₅) = 0,15 · 100 kg.
m(P₂O₅) = 15 kg.
m(P₂O₅) : M(P₂O₅) = m(P) : 2M(P).
15 kg : 142 = m(P) : 62.
m(P) = 6,55 kg.
ω(P) = 6,55 kg ÷ 100 kg · 100% = 6,55%.

3 0

3 years ago

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