Answer: <span>C) Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.</span>
Explanation:
1) This is the set of choices that comes with this question:
<span>A) Soap is a surfactant that increases the intermolecular forces of water allowing the paperclip to continue to float.</span>
<span>B) Soap makes the water less viscous making the paperclip sink.</span>
<span>C) Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.</span>
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D) Soap makes the water more viscous allowing the paperclip to continue to float.
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2) Justification:
The paperclip is denser that water, so it should sink into the water. Then, why is the paperclip floating?
The papeclip is floating due to the high surface tension of the water.
The surface tension is the force that tends to keep the molecules of a liquid together resisting the spread due to other forces (gravity for example). The surface tension is what makes that a drop of water over a table keeps round and like a hemisphere instead of spreading along all the surface of the table.
That very same force makes it possible that some insects can stand over water and is the responsible for the meniscus that you see in the thin tubes that contain water (e.g. in the test tubes in your chemistry lab).
By the way, that strong intermolecular forces that keep the molecules of water attracted to each other is due the hydrogen bonds.
The soap is a surfactant which reduces the surface tension of the water, this is it disrupts the intermolecular forces of water, and that is what the option C) tells.
Answer:
5.56 × 10^23 molecules
Explanation:
The number of molecules in a molecule can be calculated by multiplying the number of moles in that molecule by Avagadro's number (6.02 × 10^23)
Using mole = mass/molar mass
Molar mass of N2O4 = 14(2) + 16(4)
= 28 + 64
= 92g/mol
mole = 85.0/92
= 0.9239
= 0.924mol
number of molecules of N2O4 (nA) = 0.924 × 6.02 × 10^23
= 5.56 × 10^23 molecules
Answer:
Mass, m = 1.51 grams
Explanation:
It is given that,
The circumference of Aluminium cylinder, C = 13 mm = 1.3 cm
Length of the cylinder, h = 4.2 cm
We know that the density of the Aluminium is 2.7 g/cm³
Circumference, C = 2πr
Density is equal to mass per unit volume.
m is mass of the cylinder
V is the volume of the cylinder
So,
So, the mass of the cylinder is 1.51 grams.
Answer:
A horizontal line on a speed-time graph represents a constant speed. A sloping line on a speed-time graph represents an acceleration. The sloping line shows that the speed of the object is changing. The object is either speeding up or slowing down.
