Write the isotope notation for an element with 12 protons and 14 neutrons.

A scientific theory is

vlada-n [284]

The answer is A. an explanation

7 0

3 years ago

If 4.5 moles of AlCl3 were made, how many moles of CuCl2 were used?

Troyanec [42]

Answer:

6.75 moles of CuCl₂ were used

Explanation:

Given data:

Number of moles of AlCl₃ formed = 4.5 mol

Number of moles of CuCl₂ used = ?

Solution:

Chemical equation:

3CuCl₂ + 2Al → 2AlCl₃ + 3Cu

Now we will compare the moles of CuCl₂ and AlCl₃

AlCl₃ : CuCl₂

2 : 3

4.5 : 3/2×4.5 = 6.75

6.75 moles of CuCl₂ were used.

7 0

3 years ago

A 150.0 mL sample of an aqueous solution at 25°C contains 15.2 mg of an unknown nonelectrolyte compound. If the solution has an

inysia [295]

Answer: The molar mass of the unknown compound is 223.2 g/mol

Explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

$\pi=iMRT$

where,

$\pi$ = osmotic pressure of the solution = 8.44 torr

i = Van't hoff factor = 1 (for non-electrolytes)

M = molarity of solute = ?

R = Gas constant = $62.3637\text{ L torr }mol^{-1}K^{-1}$

T = temperature of the solution = $25^oC=[273+25]=298K$

Putting values in above equation, we get:

$8.44torr=1\times M\times 62.3637\text{ L. torr }mol^{-1}K^{-1}\times 298K\\\\M=\frac{8.44}{1\times 62.3637\times 298}=4.54\times 10^{-4}M$

To calculate the molecular mass of solute, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

We are given:

Molarity of solution = $4.54\times 10^{-4}M$

Given mass of unknown compound = 15.2 mg = 0.0152 g (Conversion factor: 1 g = 1000 mg)

Volume of solution = 150.0 mL

Putting values in above equation, we get:

$4.54\times 10^{-4}M=\frac{0.0152\times 1000}{\text{Molar mass of unknown compound}\times 150.0}\\\\\text{Molar mass of unknown compound}=\frac{0.0152\times 1000}{150.0\times 4.54\times 10^{-4}}=223.2g/mol$

Hence, the molar mass of the unknown compound is 223.2 g/mol

5 0

3 years ago

Ethyl acetate can be prepared by an SN2 reaction. Draw the alkylbromide and nucleophile used in the reaction. Remember to includ

bulgar [2K]

Answer:

Few important points related to $S_N2$ reaction:

1. $S_N2$ is a one-step reaction that follows second order kinetics.

2. In $S_N2$ reaction, a transition state is formed in situ.

3. Strong nucleophiles like $OH^- \ or\ CN^-$ are used in case of bi-molecular nucleophilic substitution reaction.

Ethyl acetate can be prepared by a second-order nucleophilic substitution reaction between acetic acid and ethyl bromide.

The reaction between acetic acid and ethyl bromide is drawn below:

8 0

3 years ago

Read 2 more answers

What is a problem solving by following steps to draw a conclusion?

drek231 [11]

(1) Understanding the problem
(2) Making a plan of solution
(3) Carrying out the plan

8 0

3 years ago