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 question above is simply asking us to convert the value from calories into kilojoules. Therefore, we need some factor to multiply to be able to convert it to such units. For calories to kJ, the factor would be 4.184.
2700 cal ( 4.184 kJ/cal) = 11296.8 kJ
Answer:
protons : 10
electron : 10
neutron : 10
Explanation:
Protons will usually be the same as the electrons when its a <u>Atom</u> (when its a ion or covalent bond or simple bond they will most likely be different)
the atomic number represents protons and electrons
the mass number - the atomic number = neutron
Answer:
4000 L
Explanation:
Step 1:
Data obtained from the question. This include the following:
Initial volume (V1) = 2000 L.
Initial temperature (T1) = 100 K.
Initial pressure (P1) = 100 kPa.
Final temperature (T2) = 400 K.
Final pressure (P2) = 200 kPa.
Final volume (V2) =..?
Step 2:
Determination of the new volume of the gas.
The new volume of the gas can be obtained by using the general gas equation as follow:
P1V1/T1 = P2V2/T2
100 x 2000/100 = 200 x V2/400
Cross multiply to express in linear form.
100 x 200 x V2 = 100 x 2000 x 400
Divide both side by 100 x 200
V2 = (100 x 2000 x 400)/(100 x 200)
V2 = 4000 L
Therefore, the new volume of the gas is 4000 L
The ion charge of this element, Na would be + 1, as a single valence electron has been removed and transferred to another atom, resulting in an atom with a greater number of protons than electrons, making it positively charged.
