Answer:
34.15% is the mass percentage of calcium in the limestone.
Explanation:
Mass of precipitate that is calcium oxalate = 140.2 mg = 0.1402 g
1 mg = 0.001 g
Moles of calcium oxalate = 
1 mole of calcium oxalate have 1 mole of calcium atom.
Then 0.001095 moles of calcium oxalate will have 0.001095 moles of calcium atom.
Mass of 0.001095 moles of calcium :
0.001095 mol × 40 g/mol = 0.04381 g
Mass of sample of limestone = 128.3 mg = 0.1283 g
Percentage of calcium in limestone:
34.15% is the mass percentage of calcium in the limestone.
The answer is 10 grams.
The atomic weights for each elements are :
<span>Na - 22.99 g/mol </span>
<span>O - 16.00 g/mol </span>
<span>H - 1.01 g/mol
The sum = 40 g/mol for NAOH
</span><span>0.250 moles * 40.00 g / 1 mole = 10 g NaOH</span>
Answer:
D. His device would not be successful because radio waves do not have enough energy to kill the bacteria.
Explanation:
N=9.933
Explanation:
no of mole = m÷mr
then ,no of molecules=n×la
If 45 g of O2 gas in a 500 mL container is exerting a pressure of 5.2 atm, 22.53K is the temperature in the gas.
<h3>What is an ideal gas equation?</h3>
The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
First, calculate the moles of the gas using the gas law,
PV=nRT, where n is the moles and R is the gas constant. Then divide the given mass by the number of moles to get molar mass.
Given data:
P= 5.2 atm
V= 500 mL =0.5 L
n=?
R= 
T=?
Moles = 1.40625
Putting value in the given equation:
T= 22.53167034 K= 22.53K
Hence, If 45 g of O2 gas in a 500 mL container is exerting a pressure of 5.2 atm, 22.53K is the temperature in the gas.
Learn more about the ideal gas here:
brainly.com/question/27691721
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