Answer:
Explanation:
Given that:
Pressure = 791 mmHg
Temperature = 20.0°C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (20 + 273.15) K = 293.15 K
T = 293.15 K
Volume = 100 L
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 62.3637 L.mmHg/K.mol
Applying the equation as:
791 mmHg × 1.14 L = n × 62.3637 L.mmHg/K.mol × 293.15 K
⇒n of 
produced = 0.0493 moles
According to the reaction:-
1 mole of carbon dioxide is produced 1 mole of calcium carbonate reacts
0.0493 mole of carbon dioxide is produced 0.0493 mole of calcium carbonate reacts
Moles of calcium carbonate reacted = 0.0493 moles
Molar mass of 
= 100.0869 g/mol
The formula for the calculation of moles is shown below:
Thus,
Impure sample mass = 5.28 g
Percent mass is percentage by the mass of the compound present in the sample.
The answer is <span>B. element.
An element is composed of only one kind of atom and cannot be separated into simpler substances. Oxygen (O) is the element.
A compound is a substance composed </span><span>of two or more <em>different </em>atoms chemically bonded to one another, for example, water (H</span>₂<span>O) consists of 2 atoms of hydrogen (H) and 1 atom of oxygen (O), so it is the compound.
A mixture consists of two or more substances that are not chemically combined. Solutions and colloids are mixtures.</span>
Answer:
B
Explanation:
Always remember blood first flows from atria (remember A comes before V) to ventricles and the right side always carries deoxgenated blood to the lungs which then arrives through the left side when oxygenated
Answer:
1 mole of C2H6.
Explanation:
The balanced equation for the reaction is given below:
2C2H6 + 7O2 —> 4CO2 + 6H2O
We can determine the number of mole of C2H6 that reacted to produce 2 moles of CO2 as follow:
From the balanced equation above,
2 moles of C2H6 reacted to produce 4 moles of CO2.
Therefore, Xmol of C2H6 will react to produce 2 moles of CO2 i.e
Xmol of CO2 = (2 x 2)/4
Xmol of CO2 = 1 mole.
Therefore, 1 mole of C2H6 is required to produce 2 moles of CO2.
C. rusting is the correct answer
