All categories

2 years ago

Sam investigates the reactivity of metals in air. His observations are shown below.

Chemistry

2 answers:

viva [34]2 years ago

6 0

Answer:5

Explanation:

Rufina [12.5K]2 years ago

4 0

Answer:

(a)B,D,A,C

Explanation:

You might be interested in

Is crushing a rock a chemical or physical change?

aalyn [17]

Physical change because you didn't change the chemical compound

4 0

2 years ago

Balance the following and label what type of reaction is taking place:

Vadim26 [7]

4,27,20,18

I hope this helps.

3 0

2 years ago

Which of the following is not a part of every scientific investigation?

Dmitry_Shevchenko [17]

Answer:

the correct answer is Group of answer choices

6 0

2 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]

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

Explanation:

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

2 years ago

Can u help me out its a quick question

tia_tia [17]

The second one is the way to go.

5 0

2 years ago