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2 years ago

What is the maximum volume of a 0.788 M CaCl2 solution that can be prepared using 85.3 g CaCl2

1 answer:

3 0

Molar mass CaCl₂ = 111.0 g/mol

number of moles:

n = mass of solute / molar mass

n = 85.3 / 111.0

n = 0.7684 moles of CaCl₂

M = n / V

0.788 M = 0.7684 / V

V = 0.7684 / 0.788

V = 0.97512 L

hope this helps!

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3) After a rather lengthy organic chemistry synthesis procedure, a student ran the product of the reaction on a TLC plate and obtained the result below. What might he/she have done wrong, if anything?

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5) Consider a sample that is a mixture composed of biphenyl, benzoic acid, and benzyl alcohol. The sample is spotted on a TLC plate and developed in a hexanes/ethyl acetate solvent mixture. Predict the relative Rf values for the three compounds in the sample.

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3 0

2 years ago

To determine the concentration of ethanol in cognac a 5.00 mL sample of the cognac is diluted to 0.500 L. Analysis of the dilute

julia-pushkina [17]

Answer : The molar concentration of ethanol in the undiluted cognac is 8.44 M

Explanation :

Using neutralization law,

$M_1V_1=M_2V_2$

where,

$M_1$ = molar concentration of undiluted cognac = ?

$M_2$ = molar concentration of diluted cognac = 0.0844 M

$V_1$ = volume of undiluted cognac = 5.00 mL = 0.005 L

$V_2$ = volume of diluted cognac = 0.500 L

Now put all the given values in the above law, we get molar concentration of ethanol in the undiluted cognac.

$M_1\times 0.005L=0.0844M\times 0.500L$

$M_1=8.44M$

Therefore, the molar concentration of ethanol in the undiluted cognac is 8.44 M

4 0

2 years ago

The volume of hcl gas required to react with excess ca to produce 11.4 l of hydrogen gas at 1.62 atm and 62.0 °c is ________ l.

seropon [69]

Answer:

22.8 L

Step-by-step explanation:

We can use Gay-Lussac's Law of Combining Volumes to solve this problem:

Gases at the same temperature and pressure react in simple whole-number ratios.

1. Write the chemical equation.

Ratio: 2 L 1 L

Ca(s) + 2HCl(g) ⟶ CaCl₂(s) + H₂(g)

V/L: 11.4

2. Calculate the volume of HCl.

According to the law, 2 L of HCl form 1 L of H₂.

Then, the conversion factor is (2 L HCl/1 L H₂).

Volume of HCl = 11.4 L H₂ × (2 L HCl/1 L H₂)

= 22.8 L HCl

3 0

2 years ago

The differential cross section for scattering 6.5-MeV alpha particles at 120° off a silver nucleus is about 0.5 barns/sr. If a t

Burka [1]

Answer:

Nsc=30

Explanation:

The solid angle subtended by the counter is

d=0.1mm2/(1cm)2=(10)3 sr

d=(10)10x10.5gcm3x10-4cm/108x1.6610x10-24gx0.510-24cm2x10-3=30

8 0

2 years ago

An evaporation–crystallization process of the type described in Example 4.5-2 is used to obtain solid potassium sulfate from an

timofeeve [1]

Answer:

feed = 220.77 kg/s; maximum production rate of solid crystal = 416 kg/s; the rate of supplying fresh feed to obtain the production rate = 1.6

Explanation:

Material or mass balance can be used to estimate the mass flow rates of all the streams in the diagram shown in the attached file.

Overall balance: $M_{1} = 175 + 11M_{2}$

Water: $0.804M_{1} = 175 + 0.6M_{2}$

Using substitution method, we have:

$M_{1}$ = 220.77 kg/s

$M_{2}$ = 4.16 kg/s

The maximum production rate of solid crystal is $10M_{2}$ = 10*4.16 = 416 kg/s

Around evaporator:

$0.45M_{5} = 175$

$M_{5} = 175/0.45 = 389$ kg/s

Around the mixing point:

$M_{1} + M_{3} = M_{4} + M_{5}$

Solid crystal: $0.196M_{1} + 0.4M_{3} = M_{4}$

Using the last two equations, we can obtain:

$0.804M_{1} + 0.6M_{3} = M_{5}$

$0.6M_{3} = 389 - 0.804*220.77 = 389 - 177.5 = 211.5$

$M_{3} = 211.5/0.6 = 352.5$ kg/s

The rate of supplying fresh feed to obtain the production rate is:

$\frac{M_{3}}{M_{1}}$ = 352.5/220.77 = 1.6

7 0

3 years ago