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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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Name the type of reaction shown:2C4H10+13O2=8CO2+10H2O
Sonbull [250]

Answer: It is AN combustion

reaction.

Explanation:

3 0
3 years ago
Can somebody please help me with this question, I'm very confused! I thought i did it right because i found Kb and the conc. of
andrew-mc [135]
Let's investigate the substances involved in the reaction first. The compound <span>CH3NH3+Cl- is a salt from the weak base CH3NH2 and the strong acid HCl. When this salt is hydrated with water, it will dissociate into CH3NH2Cl and H3O+:

CH3NH3+Cl- + H2O </span>⇒ CH3NH2Cl + H3O+

Nest, let's apply the ICE(Initial-Change-Equilibrium) table where x is denoted as the number of moles used up in the reaction:

                 CH3NH3+Cl- + H2O ⇒ CH3NH2Cl + H3O+
Initial                  0.51                             0               0
Change                 -x                             +x             +x
-------------------------------------------------------------------------------
Equilibrium        0.51 - x                         x               x

Then, let's find the equilibrium constant of the reaction. Since the reaction is hydrolysis we use KH, which is the ratio of Kw to Ka or Kb. Kw is the equilibrium constant for water hydrolysis which is equal to 1×10⁻¹⁴. Since the salt comes from the weak base, we use Kb. Since pKb = 3.44, then. 3.44 = -log(Kb). Thus, Kb = 3.6307×10⁻⁴ 

KH = Kw/Kb = (x)(x)/(0.51 - x)
1×10⁻¹⁴/ 3.6307×10⁻⁴ = x²/(0.51-x)
x = 3.748×10⁻⁶

Since x from the ICE table is equal to the equilibrium concentration of H+, we can find the pH of the aqueous solution:

pH = -log(H+) = -log(x)
pH = -log ( 3.748×10⁻⁶)
pH = 5.43
6 0
3 years ago
Which type of electromagnetic wave has less energy than a microwave?
polet [3.4K]
Radio waves.

From lowest to highest it is radio wave, microwave, infrared, visible light, ultraviolet, x ray, and then gamma.
7 0
2 years ago
A catalyst will
scZoUnD [109]

Answer:

increase the chemical rate

7 0
3 years ago
A sample of ammonia ^NH3h gas is completely decomposed to nitrogen and hydrogen gases over heated iron wool. If the total pressu
icang [17]

Answer : The partial pressure of N_2 and H_2 is, 216.5 mmHg and 649.5 mmHg

Explanation :

According to the Dalton's Law, the partial pressure exerted by component 'i' in a gas mixture is equal to the product of the mole fraction of the component and the total pressure.

Formula used :

p_i=X_i\times p_T

X_i=\frac{n_i}{n_T}

So,

p_i=\frac{n_i}{n_T}\times p_T

where,

p_i = partial pressure of gas

X_i = mole fraction of gas

p_T = total pressure of gas

n_i = moles of gas

n_T = total moles of gas

The balanced decomposition of ammonia reaction will be:

2NH_3\rightarrow N_2+3H_2

Now we have to determine the partial pressure of N_2 and H_2

p_{N_2}=\frac{n_{N_2}}{n_T}\times p_T

Given:

n_{N_2}=1\\\\n_{H_2}=3\\\\n_{T}=4\\\\p_T=866mmHg

p_{N_2}=\frac{1}{4}\times (866mmHg)=216.5mmHg

and,

p_{H_2}=\frac{n_{H_2}}{n_T}\times p_T

Given:

n_{H_2}=1\\\\n_{H_2}=3\\\\n_{T}=4\\\\p_T=866mmHg

p_{H_2}=\frac{3}{4}\times (866mmHg)=649.5mmHg

Thus, the partial pressure of N_2 and H_2 is, 216.5 mmHg and 649.5 mmHg

5 0
4 years ago
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