Functions of the skin other than thermoregulation

1 When a chemical reaction occurs A. the substances involved do not mix together and maintain their original properties. B. the

nlexa [21]

Answer:

D

Explanation:

The proberties of the substances that are produced are different from the properties of the original substances.

6 0

3 years ago

Calculate the weight percent of ascorbic acid in a tablet of Vitamin C from the following data:A 80 mg sample of a crushed Vitam

Lina20 [59]

Answer:

The Answer is 88%

Explanation:

The balanced ionic equation of the reaction

$IO^{3- }+ 8 I^- + 6 H^+ => 3 I^{3- }+ 3 H_2O$

$I^{3-} + 2 S_2O_3^{2-} => 3 I^- + S_4O_6^{2-}$

$C_6H_8O_6 + I^{3- }+ H_2O => C_6H_6O_6 + 3 I^- + 2 H^+$

Looking at the above reactions

The original number of moles of $I^{3-}$ = 3 × number of moles of $IO^{3-}$

= 3 × volume × concentration of $KIO_3$

Note: The formula for number of moles is volume × concentration

$=3 * \frac{40}{1000} * 0.00653 =0.000784$ mol

The number of moles of $I^{3-}$ left after its reaction with ascorbic acid

= $\frac{1}{2}$ x moles of $S_2O_3^{2-}$

= $\frac{1}{2}$ x volume x concentration of $S_2O_3^{2-}$

$= \frac{1}{2} * \frac{15}{1000} * 0.0510 =0.000383 \ mol$

Note: The division by 1000 is to convert mill liter to liter

Moles of ascorbic acid = moles of $I^{3-}$ reacted

$= initial \ moles \ of \ I^{3-} \ - remaining \ moles \ of \ I^{3-}$

$=0.000784 - 0.000383$

$=0.000401 \ mols$

$Mass = moles \ * molar \ mass$

Hence

Mass of ascorbic acid = moles of ascorbic acid × molar mass of ascorbic acid

$= 0.000401* 176.12 = 0.07055\ g$

$= 70.55\ mg$

Weight% of ascorbic acid = mass of ascorbic acid/mass of sample x 100%

= 70.55/80 × 100%

= 88.1%

3 0

4 years ago

Step 1. Carefully cut two large windows in a shoe box, as shown in the illustration. Your windows should be on opposite sides of

Alexus [3.1K]

Explanation:

1)observation is that the light doesn't reach some parts of the points of interest

2)this is because the rays of the light were interrupted by different objects thus making the light divert different ways.

4 0

3 years ago

During science class billy used litmus paper to determine the ph of an unknown liquid. the blue litmus paper turns red but there

denis-greek [22]

He was testing an acid. So your answer will be C.

Hope this helps!

3 0

4 years ago

PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEWSE HELP PLEASE H

marishachu [46]

Answer:

23.6 moles

Explanation:

From the question given above, the following data were obtained:

Mass of air = 3.6 Kg

Mass percentage of O₂ = 21%

Number of mole of O₂ =?

Next, we shall convert 3.6 Kg of air to grams (g). This can be obtained as follow:

1 kg = 1000 g

Therefore,

3.6 Kg = 3.6 Kg × 1000 / 1 kg

3.6 Kg = 3600 g

Next, we shall determine the mass of O₂ in the air. This can be obtained as follow:

Mass of air = 3600 g

Mass percentage of O₂ = 21%

Mass of O₂ =?

Mass of O₂ = 21% × 3600

Mass of O₂ = 21/100 × 3600

Mass of O₂ = 756 g

Finally, we shall determine the number of mole of O₂ in the sample of air. This can be obtained as follow:

Mass of O₂ = 756 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Number of mole of O₂ =?

Mole = mass /Molar mass

Number of mole of O₂ = 756 / 32

Number of mole of O₂ = 23.6 moles

Thus, the number of mole of O₂ in the

sample of air is 23.6 moles

7 0

3 years ago

Functions of the skin other than thermoregulation​

Functions of the skin other than thermoregulation