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liraira [26]
4 years ago
11

10g of an unknown compound are added to water to form a 7.89 molar solution. if 2 liters of solution are present, what is the mo

lar mass of the unknown compound?
Chemistry
1 answer:
Citrus2011 [14]4 years ago
6 0
10 / (7.89) (2) 

molarity equation is M = Moles of solute / Liters of solution

7.89 = Moles of solute / 2

(7.89)(2). The question asks for the molar mass which is defined as g/mol. Dividing would give you the unknown compound. 

<span>MM = 10g / (7.89)(2)</span>
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Three 5-l flasks, fixed with pressure gauges and small valves, each contains 4 g of gas at 273 k. flask a contains h2, flask b c
Varvara68 [4.7K]
First, please check the missing part in your question in the attachment.
a) So first, the Rank of pressure:
according to this formula PV = nRT and when n = m/Mw
PV = m/Mw * R*T
when we have the same mass m and the same V volume so P will proportional with the mole weight M as when the M is smaller the pressure will be greater 
when Mw of H2(A) = 2 g / Mw of He (B) = 4 g and Mw of CH4(C) = 16 g
∴ Pressure :
 (A) > (B) > (c)

B) The rank of average molecular kinetic energy:
when K = 3/2 KB T
when K is the average kinetic energy per molecule of gas 
and KB is Boltzmann's constant
and T is the temperature (K)
So from this equation, we can know that K only depends on T value, and when we have the T constant here for A, B, and C So the rank of K will be like the following:
∴ A = B = C
C) the rank of diffusion rate after the valve is opened:
according to this formula:
R2/R1 = √M1/M2
from this equation, we can see that diffusion is proportional to the reciprocal of the molecular mass M so,
when Mw H2 (A) = 2 g & Mw He(B) = 4 g & CH4 (C) = 16 g
∴ the rank of diffusion:
A > B > C

D) The rank of the Total kinetic energy of the molecules:
when we have the Mw different so it will make the no.of molecules differs as when the Mw is low the no.of molecules will be hight, and when the average molecular kinetic energy equals. so the total kinetic energy will depend on no. of molecules 
∵ Mw A < Mw B < Mw C 
∴no .of molecules of A > B >C
∴ the rank of total kinetic energy is:
A > B > C

e) the rank of density:

when ρ = m/ v 
and m is the mass & v is the volume and we have both is the same for A, B, and C
so the density also will be the same, ∴ the rank of the density is:
A = B = C

F) the rank of the collision frequency:
as the no.of molecules increase the collision frequency increase and depend also on the velocity and it's here the same.
∴ Collision frequency will only depend on the no.of molecules
we have no.of molecules of A > B > C as Mw A < B < C 
∴the rank of the collision frequency is:
A > B > C 

 



7 0
3 years ago
Without using Appendix B, predict the sign of ΔS° for(b) KBr(s)→ KBr(aq)
Volgvan

Since the sign is positive, the entropy increased by 88.48 J/K.

Examine the phases of the species present to determine whether a physical or chemical process will cause an increase or decrease in entropy. Keep in mind "Silly Little Goats" to aid you in telling.

[1 Sf K+1 + 1 Sf Br-1 (aq)] ([1Sf(KBr (s))])

[1(102.5) + 1(82.42)] - [1(96.44)] = 88.48 J/K

If the entropy has grown, we say that Delta S is positive, and if it has dropped, we say that Delta S is negative. Due to its ionic nature, KBr is soluble in water and causes the 'K(+)' ions to hydrate.

Learn more about Entropy here-

brainly.com/question/13146879

#SPJ4

8 0
2 years ago
Which is a measurement of distance that is used around the world?
ivolga24 [154]
500 meters is the correct answer :)
8 0
3 years ago
Read 2 more answers
Filtration, or screening, is one way to separate certain mixtures, as shown in the image. Which of these mixtures could be most
erastovalidia [21]

Answer: D

Explanation:

3 0
3 years ago
If the pressure of a gas is 1.01 atm and the temperature is 25°C, then if the pressure is increased to 1.10, what is the new tem
vodka [1.7K]

Answer:

T2 = 51.6°C

Explanation:

Given:

P1 = 1.01 atm

T1 = 25°C + 273 = 298K

P2 = 1.10 atm

T2 = ?

P1/T1 = P2/T2

Solving for T2,

T2 = (P2/P1)T1

= (1.10 atm/1.01 atm)(298K)

= 324.6 K

= 51.6°C

where Tc = Tk - 273

3 0
3 years ago
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