The mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the number of moles of a substance by its molar mass. That is;
Mass of Arsenic = no. of moles of As × molar mass of As.
According to this question, 6.12 moles of arsenic was given and its molar mass is 74.92g/mol.
Mass of As = 6.12 mol × 74.92g/mol
Mass of As = 459g
Therefore, the mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.
Learn more about mass calculations at: brainly.com/question/8101390
Answer:
Entropy increases
Explanation:
Entropy (S) is a measure of the degree of disorder. For a given substance - say water - across phases the following is true ...
S(ice) < S(water) << S(steam)
For a chemical process, entropy changes can be related to increasing or decreasing molar volumes of gas from reactant side of equation to product side of equation. That is ...
if molar volumes of gas increase, then entropy increases, and
if molar volumes of gas decrease, then entropy decreases.
For the reaction 2KClO₃(s) => 2KCl(s) + 3O₂(g)
molar volumes of gas => 0Vm* 0Vm 3Vm
*molar volumes (Vm) apply only to gas phase substances. Solids and liquids do not have molar volume.
Since the reaction produces 3 molar volumes of O₂(g) product vs 0 molar volumes of reactant, then the reaction is showing an increase in molar volumes of gas phase substances and its entropy is therefore increasing.
CH4 + 2O2→CO2 + 2H2O
Explanation:
CH4 + O2→CO2 + H2O
First look at the C atoms. At first glance they are balanced with 1 C on each side.
Now look at the H atoms. They are not balanced. There are 4 H atoms on the left side and 2 H atoms on the right. Place a coefficient of 2 in front of the H2O. We now have 4 H atoms on both sides.
CH4 + O2→CO2 + 2H2O
Now look at the O atoms. They are not balanced. There are 2 O atoms on the left side and 4 on the right. Place a coefficient of 2 in front of the O2. We now have 4 O atoms on both sides.
CH4 + 2O2→CO2 + 2H2O
The equation is now balanced. Each side has 1 C atom, 4 H atoms, and 4 O atoms.
Option 2: 12.0 L of 
at STP.
The standard pressure and temperature values are 1 atm and 273.15 K.
Using the ideal gas equation, number of moles of gas can be calculated which is as follows:
PV=nRT...... (1)
Here, P is pressure, V is volume, n is number of moles, R is gas constant and T is temperature.
Also, in 1 mole of any gas there are 
molecules of the gas. This is known as Avogadro's number and denoted by symbol 
Thus,
Equation (1) can be rewritten as follows:
On rearranging,
Here, all the other terms are constant except volume, thus, gas with volume equal to the volume of 
will have same number of molecules.
Volume of gas and 
gas is same thus, will have same total number of molecules as gas.
Answer:
4 sig figs
Explanation:
<h3>Rule when dividing or multiplying:</h3>
After normally solving the expression cut round the decimal to the least accurate of the two.
54.50/50.407 = 1.08119904
Since 54.50 is the least accurate we will round to the hundredths place.
1.081 is final answer
so there are 4 sig figs.
