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Stella [2.4K]
3 years ago
8

What does index fossil mean?

Chemistry
1 answer:
marysya [2.9K]3 years ago
3 0

An index fossil is a  fossil that is useful for dating and correlating the strata in which it is found.

Or it is a fossil that helps you find the date where it has been found. I rephrased that.

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22. Which one of the following processes has a negative value for AH°?
ss7ja [257]

Answer:

C

Explanation:

A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.

Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.

A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.

C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.

D requires heat. It is not the answer.

4 0
4 years ago
What enzyme catalyzes the conversion of carbon dioxide and water to carbonic acid, and where is this enzyme located
adoni [48]

Answer:

Carbonic anhydrase and they are located in renal tubules.

Explanation:

7 0
2 years ago
What is the mean free path for the molecules in an ideal gas when the pressure is 100 kPa and the temperature is 300 K given tha
sladkih [1.3K]

Answer:

The mean free path = 2.16*10^-6 m

Explanation:

<u>Given:</u>

Pressure of gas P = 100 kPa

Temperature T = 300 K

collision cross section, σ = 2.0*10^-20 m2

Boltzmann constant, k = 1.38*10^-23 J/K

<u>To determine:</u>

The mean free path, λ

<u>Calculation:</u>

The mean free path is related to the collision cross section by the following equation:

\lambda =\frac{1}{n\sigma }------(1)

where n = number density

n = \frac{P}{kT}-----(2)

Substituting for P, k and T in equation (2) gives:

n = \frac{100,000 Pa}{1.38*10^{-23} J/K*300K} =2.42*10^{25}\  m^{3}

Next, substituting for n and σ in equation (1) gives:

\lambda =\frac{1}{2.42*10^{25}m^{-3}* .0*10^{-20}m^{2}}=2.1*10^{-6}m

6 0
3 years ago
A reaction is spontaneous if ΔG is ___?<br> negative, positive, or zero?
amm1812

Answer:

A reaction is spontaneous if ΔG is negative.

Explanation:

  • The change in free energy (ΔG) is the difference between the heat released during a process and the heat released for the same process occurring in a reversible manner.

  • The sign of ΔG gives an indication for the spontaneity of the reaction:

If ΔG is negative, the reaction is spontaneous.

If ΔG = zero, the reaction is at equilibrium.

If ΔG is positive, the reaction is non-spontaneous.

3 0
4 years ago
What is the difference between accuracy and precision in chemistry ?
earnstyle [38]
Accuracy is more of a range 
6 0
4 years ago
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