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noname [10]
3 years ago
6

Someone please help me it'll mean a lot

Chemistry
1 answer:
creativ13 [48]3 years ago
6 0
Average atomic mass is 238.02891 
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An object has a mass of 6.8 g and volume of 34 mL. What is the density of the object?​
jenyasd209 [6]

Answer:

<h2>Density = 0.2 g/mL</h2>

Explanation:

The density of a substance can be found by using the formula

<h3>Density =  \frac{mass}{volume}</h3>

From the question the points are

mass = 6.8 g

volume = 34 mL

Substitute the values into the above formula and solve

That's

<h3>Density =  \frac{6.8}{34}</h3>

We have the final answer as

<h3>Density = 0.2 g/mL</h3>

Hope this helps you

7 0
3 years ago
2. if 0.20 m fe3 had been used instead of 0.020 m fe3 , how would the numerical value of the rate constant and the activation en
dezoksy [38]

the calculated value is Ea is 18.2 KJ and A is 12.27.

According to the exponential part in the Arrhenius equation, a reaction's rate constant rises exponentially as the activation energy falls. The rate also grows exponentially because the rate of a reaction is precisely proportional to its rate constant.

At 500K, K=0.02s−1

At 700K, k=0.07s −1

The Arrhenius equation can be used to calculate Ea and A.

RT=k=Ae Ea

lnk=lnA+(RT−Ea)

At 500 K,

ln0.02=lnA+500R−Ea

500R Ea (1) At 700K lnA=ln (0.02) + 500R

lnA = ln (0.07) + 700REa (2)

Adding (1) to (2)

700REa100R1[5Ea-7Ea] = 0.02) +500REa=0.07) +700REa.

=ln [0.02/0 .07]

Ea= 2/35×100×8.314×1.2528

Ea =18227.6J

Ea =18.2KJ

Changing the value of E an in (1),

lnA=0.02) + 500×8.314/18227.6

= (−3.9120) +4.3848

lnA=0.4728

logA=1.0889

A=antilog (1.0889)

A=12.27

Consequently, Ea is 18.2 KJ and A is 12.27.

Learn more about Arrhenius equation here-

brainly.com/question/12907018

#SPJ4

5 0
2 years ago
What are the primary chemical components present in a phosphate buffer at ph 7.4? H3po4 and po43–?
fenix001 [56]

Answer :

The correct answer for primary component of phosphate buffer at pH = 7.4 is H₂PO₄⁻ and HPO₄²⁻ .

<u>Buffer solution :</u>

It is a solution of mixture of weak acid and its conjugate base OR weak base and its conjugate acid . It resist any change in solution when small amount of strong acid or base is added .

<u>Capacity of a good buffer : </u>

A good buffer is identified when pH = pKa .

From Hasselbalch - Henderson equation which is as follows :

pH = pka + log \frac{[A^-]}{[HA]}

If [A⁻] = [HA] ,

pH = pka + log 1

pH = pKa

This determines that if  concentration of  weak acid  and its conjugate base are changed in small quantity , the capacity of  buffer to maintain a constant pH is greatest at pka .  If the amount of [A⁻] or [HA] is changed in large amount , the log value deviates more than +/-  1M and hence pH .

Hence Buffer has best capacity at pH = pka .

<u>Phosphate Buffer : </u>

Phosphate may have three types of acid-base pairs at different pka ( shown in image ).

Since the question is asking the pH = 7.4

At pH = 7.4 , the best phosphate buffer will have pka near to 7.4 .

If image is checked the acid - base pair  " H₂PO₄⁻ and HPO₄²⁻  has pka 7.2 which is near to pH = 7.4 .

Hence we can say  , the primary chemical component of phosphate buffer at pH = 7.4  is H₂PO₄⁻ and HPO₄²⁻  .


8 0
3 years ago
Which two atoms represent isotopes of the same element
inysia [295]
D & e represent the same element
6 0
3 years ago
What does control group mean
fiasKO [112]
A control group is the group in an experiment that does not receive any sort of change, to then be compared to the other treated objects at the end of the study.
7 0
3 years ago
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