Answer:
D. the mass of one mole of a substance
Explanation:
The molar mass of a substance is the mass in grams of one mole of the substance.
- For an element, the molar mass is the relative atoms mass expressed in grams.
- For example 23g of Na, 40g of oxygen
- For compounds, molar mass is the gram -formula or gram - molecular weight.
- This is determined by the addition of its component atomic masses and then expressed in grams.
Molarity= moles/ liters
first you need to calculate the moles using the molar mass of the molecule to convert grams to moles
molar mass MgO= 40.3 grams/ mole
62.5 gram MgO (1 mole/ 40.3 grams)= 1.55 mole
Molarity= 1.55 mole/ 1.50 Liters= 1.03 M
Answer: Naprox 350 is the anwser
Explanation: because to fourmals mixed makes naprox know as gr27
Let's begin with the basic values that will be used in the solution.
The formula of propane is C3H8. It is an alkane, a hydrocarbon with the general formula of CnH2n+2. Notice that hydrocarbons have only Carbon and Hydrogen atoms. Its molar mass (M) is 44 g.
Molar Mass Calculation is done as like that
C=12 g/mol, H=1 g/mol. 1 mole propane has 3 moles Carbon atoms and 8 mole Hydrogen atoms. M(C3H8)= 3*12+ 8*1= 44 g
Combustion reaction of hydrocarbons gives carbon dioxide and water by releasing energy. That energy is called as enthalpy of combustion (ΔHc°).
ΔHc° of propane equals -2202.0 kj/mol. Burning of 1 mole C3H8 releases 2202 kj energy. Minus sign only indicates that the energy is given out ( an exothermic reaction ).
Let's write the combustion reaction.
C3H8 + O2 ---> CO2 + H20 (unbalanced) ΔHc° = -2202 kj/mol
Now, we calculate mole of 20 kg propane. Convert kilogram into gram since we use molar mass is defined in grams.
mole=mass/molar mass ; n=m/M ; n= 20000 g /44 (g/mol)=454 mole
1 mole propane releases 2202 kj energy.
454 mole propane release 2202 kj *454= 1000909 kj
The answer is 1000909 kj.
