If we change the pH of a substance is this a physical change chemical change or both?

Which part(s) of a telephone involves the conversion of sound waves to electrical signals?

Karo-lina-s [1.5K]

I believe that the answer would be D, both the speaker and the microphone

3 0

3 years ago

Name two "Storage Polysaccharides" and two "Structural Polysaccharides"

Vsevolod [243]

Answer:

Examples of storage polysaccharides - <u>starch and glycogen</u> and structural polysaccharides - <u>cellulose and chitin</u>

Explanation:

Polysaccharides are the complex carbohydrate polymers, composed of monosaccharide units that are joined together by glycosidic bond.

In other words, polysaccharides are the carbohydrate molecules that give monosaccharides or oligosaccharides on hydrolysis.

The examples of storage polysaccharides are starch and glycogen. The examples of structural polysaccharides are cellulose and chitin.

6 0

3 years ago

What is the name of the contact force that works in opposite direction of the motion?

nignag [31]

Answer:

may be uniform motion .,.

3 0

3 years ago

Calculate the mass of oxygen (in mg) dissolved in a 5.00 L bucket of water exposed to a pressure of 1.13 atm of air. Assume the

REY [17]

Explanation:

It is known that relation between partial pressure, mole fraction and pressure is as follows.

Partial pressure of gas = mole fraction of gas × Pressure of gas

Therefore, putting the given values into the above formula as follows.

Partial pressure of gas = mole fraction of gas × Pressure of gas

= $0.21 \times 1.13 atm$

= 0.237 atm

According to Henry's law,

Concentration of oxygen = Henry's law constant × partial pressure of oxygen

= $1.3 \times 10^{-3} M/atm \times 0.2373 atm$

= $3.08 \times 10^{-4}$ M

Therefore, calculate moles of oxygen in 5.00 L present as follows.

Moles of oxygen in 5.00 L = volume × concentration

= $5.00 \times 3.0849 \times 10^{-4}$

= $1.542 \times 10^{-3}$ mol

Now, we will calculate the mass of oxygen as follows.

Mass of oxygen = moles × molar mass of oxygen

= $1.542 \times 10^{-3} mol \times 32 g/mol$ mol

= 0.0494 g

or, = 49.4 mg (As 1 g = 1000 mg)

thus, we can conclude that the mass of given oxygen (in mg) is 49.4 mg.

5 0

3 years ago

Upon landing, the 90.7 kg carbon fiber brakes of an airliner heat up 312∘C, producing heat. As the brakes start to cool back to

Crank

Given,

Mass of carbon fiber brakes = 90.7 kg = 90.7 x 1000 = 90700 g

Mass of the rubber tires = 123 kg = 123 x 1000 = 123000

Specific heat of carbon fiber = 1.400Jg∘C

As all the heat is transferred from the carbon fiber brakes to the rubber tires, the heat lost by the carbon fiber brakes is equal to the heat gained by the rubber tires.

So the temperature change of carbon fiber brakes, delta T = 172∘C

And the temperature change of rubber tires, delta T = 172∘C

The formula used for heat is,

Q = m s delta T

where Q is heat, m is mass, s is specific heat, and delta T is the temperature change

We know,

Heat lost by the carbon fiber brakes = Heat gained by the rubber tires

90700 g x 1.400Jg∘C x 172∘C = 123000 g x s x 172∘C

or, 90700 g x 1.400Jg∘C = 123000 g x s

or, s = (90700 g x 1.400Jg∘C) / 123000 g

or, s = 1.03236

Therefore, the specific heat of rubber tires is 1.03236 Jg∘C

8 0

3 years ago

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