Volume = 250 mL in liters : 250 / 1000 => 0.25 L
Molarity = 0.85 M
Number of moles:
n = M x V
n = 0.85 x 0.25
n = 0.21 moles
Choice B
Answer:
Explanation:
Physical properties and physical change:
Physical properties are the properties of substance that do not involve the change in to another matter while the process through which change is happen is called physical change.
For example,
Melting point is physical property and the process "melting" is called physical change.
Freezing point is physical property and the process "freezing" is called physical change.
Chemical property and chemical change:
Chemical property is the ability of substance to change into another substance while the process through through which it is happen is called chemical change or chemical reaction.
For example:
The chemical property of iron is to react with oxygen and form rust. This process or chemical change is called corrosion. So corrosion is chemical change.
Hydrocarbon react with oxygen and form water and carbon dioxide. It is the chemical property. While the process is called combustion so combustion is a chemical change.
Answer:
Because it helps the filament from decaying
Answer:
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
Explanation:
Molarity of the solution is the moles of compound in 1 Liter solutions.

Mass of NaOH = x
Molar mass of NaOH = 40 g/mol
Volume of the NaOH solution = 450 mL =- 0.450 L ( 1 ml = 0.450 L)
Molarity of the solution of NaOH = 0.250 M


Solving for x:
x = 4.5 g
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
The answer is A because if you place the first two numbers 1 and 3
Au=2
S=3
H=6
It has to equal to the product so then you put in the last two numbers 2 and 3
Au=2
S=3
H=6