All categories

3 years ago

What do these substances have in common?

Chemistry

2 answers:

Romashka-Z-Leto [24]3 years ago

6 0

They are all compounds.

(i took the test)

Hope i helped! :)

Akimi4 [234]3 years ago

4 0

They are compounds Good Luck!

You might be interested in

Can you plz help me with this question? thanks! question 6

spayn [35]

Sorry can't see clearly

8 0

3 years ago

(1.) Using Beer's Law, How will the absorbance measured for the solutions change as the concentration of aspirin in solutions in

Vesnalui [34]

Answer:

(1) The absorbance of the aspirin in solutions will increase.

(2) [ASA]f = 3.79x10⁻⁴M

(3) [ASA]i = 3.79x10⁻³M

(4) m ASA = 0.171g

Explanation:

The Beer's Law is expressed by:

$A = \epsilon \cdot l \cdot C$ (1)

where A: is the absorbance of the species, ε: is the molar attenuation coefficient, l: is the pathlength and C: is the concentration of the species

(1) From equation (1), the relation between the absorbance of the species and its concentration is directly proportional, so if the aspirin concentration in solutions increases, the absorbance of the solutions will also increase.

(2) Starting in the given expression for the relationship between absorbance and concentration of ASA, we can calculate its concentration in the solution:

$A = 1061.5 \cdot [ASA]$

$[ASA] = \frac{A}{1061.5} = 3.79 \cdot 10^{-4}M$

Therefore, the aspirin concentration in the solution is 3.79x10⁻⁴ M

(3) To calculate the stock solution concentration, we can use the next equation:

$V_{i} [ASA]_{i} = V_{f} [ASA]_{f}$

where Vi: is the stock solution volume=10mL, Vf: is the solution diluted volume=100mL, [ASA]i: is the aspirin concentration of the stock solution and [ASA]f: is the aspirin concentration of the diluted solution

$[ASA]_{i} = \frac{V_{f} \cdot [ASA]_{f}}{V_{i}} = \frac {100mL \cdot 3.79\cdot 10^{-4} M}{10mL} = 3.79 \cdot 10^{-3} M$

Hence, the concentration of the stock solution is 3.79x10⁻³M

(4) To determine the aspirin mass in the tablet, we need to use the following equation:

$m_{ASA} = \eta_{ASA} \cdot M_{ASA} = [ASA]_{i} \cdot V_{0} \cdot M_{ASA}$

where η: is the aspirin moles = [ASA]i V₀, M: is the molar mass of aspirin=180.158g/mol, V₀: is the volume of the volumetric flask=250mL and [ASA]i: is the aspirin concentration in the volumetric flask which is equal to the stock solution=3.79x10⁻³M

$m_{ASA} = 3.79 \cdot 10^{-3} \frac{mol}{L} \cdot 0.250L \cdot 180.158 \frac{g}{mol} = 0.171 g$

Then, the aspirin mass in the tablet is 0.171 g.

I hope it helps you!

5 0

3 years ago

Do you think the tectonic plates are still moving today?why?

jek_recluse [69]

Yes, The tectonic plates are always moving and interacting today. The continents are still moving today. Because sometimes of the most dynamic sites of tectonic activity are seafloor spreading zones and giant rift valleys.

3 0

2 years ago

The volume of a sample of hydrogen is 771.8 mL and it exerts 638.7 mm Hg pressure at 6.5 ºC. What volume does it occupy at stand

slamgirl [31]

Answer:

627mL (May be something is wrong with the choices)

Explanation:

First step: Ideal gas Law to get the moles

P . V = n . R . T

where P is pressure in atm (638.7 mmHg)

V is volume in L

n, the number of moles, the unknow value at this time

R the Ideal gas constant 0.082 L.atm/mol.K

T, the temperature in K (°C + 273)

760 mmHg ___ 1 atm

638.7 mmHg ___ (638.7 /760) = 0.84 atm

771,8 mL / 1000 = 0.7718 L

6.5°C + 273 = 279.5 K

0.7718 L . 0.84atm = n. 0.082 L.atm/mol.K . 279.5K

0.7718 L . 0.84atm /0.082 mol.K/L.atm . 279.5K = n

0,028 moles = n

Standard temperature and pressure are 273K and 1 atm

1 atm . Volume = 0,028 moles . 0.082 L.atm/mol.K . 273K

Volume = (0,028 moles . 0.082 L.atm/mol.K . 273K) /1atm

Volume = 0,6268 L = 627mL

5 0

3 years ago

ASAP

dalvyx [7]

Answer:

electric?

Explanation:

7 0

4 years ago

Read 2 more answers