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3 years ago

At STP, what volume do these gases occupy? a. 1.25 mol He b. 0.335 mol C2H6

1 answer:

6 0

A. $\frac{1.25 mol}{1} * \frac{22.4 L}{1 mol} =28.1 L$
b. $\frac{0.335 mol C2H6}{1} * \frac{22.4 L}{1 mol} =7.50 L C2H6$

22.4 L = 1 mol at STP

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Be sure to answer all parts. Part 1 out of 2 how many electrophilic centers are present in acetyl chloride (ch3cocl)?

natima [27]

<h3>Answer:</h3>

There is One electrophilic center in acetyl chloride.

<h3>Explanation:</h3>

Electrophile is defined as any specie which is electron deficient and is in need of electrons to complete its electron density or octet. The main two types of electrophiles are those species which either contain positive charge (i.e. NO₂⁺, Cl⁺, Br⁺ e.t.c) or partial positive charge like that contained by the sp² hybridized carbon of acetyl chloride shown below in attached picture.

In acetyl chloride the partial positive charge on sp² hybridized carbon is generated due to its direct bonding to highly electronegative elements *with partial negative charge) like oxygen and chlorine, which tend to pull the electron density from carbon atom making it electron deficient and a good electrophile for incoming nucleophile as a center of attack.

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3 years ago

A solution made by dissolving 33 mg of insulin in 6.5 mL of water has an osmotic pressure of 15.5 mmHg at 25°C. Calculate the mo

Liula [17]

<u>Answer:</u> The molar mass of the insulin is 6087.2 g/mol

<u>Explanation:</u>

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

$\pi=iMRT$

Or,

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

where,

$\pi$ = osmotic pressure of the solution = 15.5 mmHg

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

Mass of solute (insulin) = 33 mg = 0.033 g (Conversion factor: 1 g = 1000 mg)

Volume of solution = 6.5 mL

R = Gas constant = $62.364\text{ L.mmHg }mol^{-1}K^{-1}$

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

Putting values in above equation, we get:

$15.5mmHg=1\times \frac{0.033\times 1000}{\text{Molar mass of insulin}\times 6.5}\times 62.364\text{ L.mmHg }mol^{-1}K^{-1}\times 298K\\\\\text{molar mass of insulin}=\frac{1\times 0.033\times 1000\times 62.364\times 298}{15.5\times 6.5}=6087.2g/mol$

Hence, the molar mass of the insulin is 6087.2 g/mol

8 0

3 years ago

If energy was added to solid, what state would it change to

12345 [234]

Answer:

Explanation:

The answer is C Liquid

7 0

3 years ago

Read 2 more answers

Milk of magnesia, a suspension of mg(oh)2 in water, reacts with stomach acid (hcl) in a neutralization reaction. mg(oh)2(s) + 2

defon

Balanced equation for the above reaction is as follows;
Mg(OH)₂ + 2HCl ---> MgCl₂ + 2H₂O
stoichiometry of Mg(OH)₂ to MgCl₂ is 1:1
mass of Mg(OH)₂ reacted - 1.82 g
number of moles of Mg(OH)₂ - 1.82 g/ 58.3 g/mol = 0.0312 mol
number of Mg(OH)₂ moles reacted - number of MgCl₂ moles formed
number of MgCl₂ moles formed - 0.0312 mol
mass of MgCl₂ formed - 0.0312 mol x 95.2 g/mol = 2.97 g
mass of MgCl₂ formed - 2.97 g

5 0

3 years ago

Choose a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, jus

Ugo [173]

Answer:

A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher

D. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.

Explanation:

Sand absorbs water and stores it. The sunlight causes the water to evaporate but sand can hold some of the water inside it. This results in increase in mass of the sand. The mass of sand before and after the water evaporation can be different.

6 0

3 years ago