In order to determine the number of molecules of nitrogen dioxide that are in 1.28 g of nitrogen dioxide, we first need to know these values:
Molar mass of nitrogen dioxide = 46.0055 g/mol
Avogadro's number = 6.022 x 10^23 molecules/mol
Then, we divide 1.28 g by the molar mass and multiply the resulting value to Avogadro's number:
1.28 g/ 46.0055 g/mol x 6.022 x 10^23 molecules/mol = 1.6755 x 10^22 molecules of nitrogen dioxide
Answer:
The answer to your question is 0.35 moles of ZnCl₂
Explanation:
Data
moles of ZnCl₂ = ?
mass of Zn = 23 g
mass of CuCl₂ = excess
Balanced chemical reaction
Zn + CuCl₂ ⇒ ZnCl₂ + Cu
Process
1.- Convert the mass of Zn to moles
-Look for the atomic mass of Zn
Atomic mass = 65.4 g
-Convert the grams to moles
65.4 g -------------- 1 mol
23 g ---------------- x
x = (23 x 1)/65.4
x = 23 / 65.4
x = 0.35 moles of Zn
2.- Calculate the moles of ZnCl₂ using proportions and cross multiplication, and the coefficients of the balanced chemical reaction.
1 mol of Zn ---------------- 1 mol of ZnCl₂
0.35 moles of Zn -------- x
x = (0.35 x 1) / 1
x = 0.35 moles of ZnCl₂
Answer:
Some energy is lost as heat
Explanation:
It is correct to say that as the gasoline is converted to mechanical energy in the automobile engine, some of the energy is lost as heat.
Heat energy is on of the ways energy is lost in any system. The movement of mechanical parts and even the combustion of the gasoline produces heat energy.
These energy are usually lost to the environment.
A compound is a pure substance formed by the chemical combination of two or more different elements.
A compound may be splitted into simpler substances by chemical reactions, and has different properties to those of the elements that form it.
The composition of a compound is fixed: every piece of a compound has the same kind of atoms, bonded in the same way and proportion.
Some examples of compounds are H₂O, NaCl, H₂O₂, CH₃COOH. As you see, they have a chemical formula which states the kind and number of the atoms that form them.
They are different to mixtures, which are formed by two or more compounds, in a variable proportion, and can be separated by physical media. Some examples of mixtures are the solutions (e.g. NaCl dissolved in H₂O), and some solid mixtures (e.g. a mixture of marbles and sand).
Ca=40
C=12
O=16
1 mole of CaCO3 has 100 grams
So 50 grams is 0.5 mole