We are given that 1 teaspoon is equivalent to 5 mL,
therefore 0.75 teaspoon is:
0.75 teaspoon * (5 mL / 1 teaspoon) = 3.75 mL
So the mass is density times volume:
mass = (12.5 mg/5 ml) * 3.75 mL
<span>mass = 9.375 mg</span>
Answer:
Weathering is the breakdown of rock by natural forces and chemical changes
Explanation:
The air and water (rain) are natural forces that breaks down rocks
<span>Pre-1982 definition of STP: 37 g/mol
Post-1982 definition of STP: 38 g/mol
This problem is somewhat ambiguous because the definition of STP changed in 1982. Prior to 1982, the definition was 273.15 K at a pressure of 1 atmosphere (101325 Pascals). Since 1982, the definition is 273.15 K at a pressure of exactly 100000 Pascals). Because of those 2 different definitions, the volume of 1 mole of gas is either 22.414 Liters (pre 1982 definition), or 22.71098 liters (post 1982 definition). And finally, there's entirely too many text books out there that still use the 35 year obsolete definition. So let's solve this problem using both definitions and you need to pick the correct answer for the text book you're using.
First, determine how many moles of gas you have. Just simply divide the volume you have by the molar volume.
Pre-1982: 2.1 / 22.414 = 0.093691443 moles
Post-1982: 2.1 / 22.71098 = 0.092466287 moles
Now determine the molar mass. Simply divide the mass by the moles. So
Pre-1982: 3.5 g / 0.093691443 moles = 37.35666667 g/mol
Post-1982: 3.5 g / 0.092466287 moles = 37.85163333 g/mol
Finally, round to 2 significant figures. So
Pre-1982: 37 g/mol
Post-1982: 38 g/mol</span>
Answer:
Explanation:
Hello,
In this case, since the reaction between potassium hydroxide and nitric acid is:
We can see a 1:1 mole ratio between the acid and base, therefore, for the titration analysis, we find the following equality at the equivalence point:
That in terms of molarities and volumes is:
Thus, solving the molarity of the base (KOH), we obtain:
Regards.
A B and C are all chemical changes. paper tearing is not.
