Answer:
C. A Spring Scale
Explanation:
Using process of elimination, we can quickly decide that a stopwatch and a ruler will not be useful in measuring the force. This leaves us with either the spring scale or a balance scale. A balance scale is used to compare two weights, so this is eliminated. That leaves us with a spring scale. This is because we can attached the spring scale to the car and when we let it go, we can record the force. I hope this helps!
The very last option is the correct answer.
Answer:
A. A physical change took place during this experiment
Explanation:
A physical change is one of the changes that occurs in a reaction. It is a kind of change characterized by no change to the chemical composition of the substances involved. It involves reactions such as melting, change of state, freezing, boiling etc.
According to this question, Lydia added 50 grams of sugar to 200 milliliters of water, then, stirred the mixture, until the sugar eventually dissolved into the water and couldn’t be seen. This change involved no change in color, odor, or temperature. Hence, Lydia's experiment represents a PHYSICAL CHANGE because only DISSOLUTION occured.
In an experiment, Lydia added 50 grams of sugar to 200 milliliters of water. She stirred the mixture, and the sugar eventually dissolved into the water and couldn’t be seen. The volume of the solution increased, but there was no noticeable change in color, odor, or temperature. Which statement best describes what happened in Lydia’s experiment? A. A physical change took place during this experiment. B. A chemical change took place during this experiment. C. A compound was formed during this experiment. D. A heterogeneous mixture was
Answer: 1.85M
Explanation:
Sodium hydroxide has a chemical formula of NaOH
Given that,
Amount of moles of NaOH (n) = ?
Mass of NaOH in grams = 63g
For molar mass of NaOH, use the molar masses:
Sodium, Na = 23g;
Oxygen, O = 16g;
Hydrogen, H = 1g
NaOH = (23g + 16g + 1g)
= 40g/mol
Since, amount of moles = mass in grams / molar mass
n = 63g / 40.0g/mol
n = 1.575 mole
Volume of NaOH solution (v) = 850mL
[Convert 850mL to liters
If 1000mL = 1L
850mL = 850/1000 = 0.85L]
Concentration of NaOH solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 1.575 mole / 0.85L
c = 1.85M [1.85M is the concentration in moles per litres which is also known as molarity]
Thus, the molarity of the solution is 1.85M