Answer:
At the burner temp. and pressure, 18.85 litres of air is needed to completely combust each gram of propane
Explanation:
The combustion stoichiometry is as follows:
C₃H₈ + 5O₂ = 4 H₂O + 3CO₂ The molecular weights (g/mol) are:
MW 44 5x32 4x18 3x44
So each gram of propane is 1/44 = 0.02272 mol propane
and will need 5 x 0.02272 = 0.1136 mol oxygen
At 0.21 mol fraction oxygen in air, 0.1136 / 0.21 = 0.54 mol air is needed to burn the propane.
At the low pressure in the burner we can use the Ideal Gas Law
PV=nRT, or V = nRT/P
P = 1.1 x 101325 Pa = 111457 Pa
T = 195°C + 273 = 468 K
R = 8.314
and we calculated n = number of moles air = 0.54 mol
So V m³ = 0.54 x 8.314 x 468 / 111457 = 0.0188 m³ = 18.85 litres air.
A sour-tasting material (usually in a solution) that dissolves metals and other materials. Technically, a material that produces positive ions in solution. An acid<span> is the opposite of a base and has a pH of 0 to 7.</span>
Answer:
Option (A)
Explanation:
Radioactivity is defined as a process in which an unstable atomic nucleus decays continuously and after a specific period of time changes into a much more stable element. During this time of decay, the nucleus emits charged particles (energy) which are known as the α, β and γ particles. These are often emitted in the form of electromagnetic energy and are very dangerous to health.
The radioactive elements decay at a certain rate which is commonly known as the half-life. Half-life is basically defined as the time required by a radioactive substance to decay half of its initial composition.
Thus, the correct answer is option (A).
Each covalent H bond is nonpolar.
Answer:
See explanation
Explanation:
Let us recall that a negative ion is formed by addition of electrons to an atom. When electrons are added to the atom, greater interelectronic repulsion increases the size of the Te^2− hence it is greater in size than Te atom. Therefore, the ionic radius of Te^2− is greater than the atomic radius of Te.
In the second question, oxygen is positioned so far to the right because it has a far smaller nuclear charge compared to Te. Hence in the PES spectrum, the 1s sublevel of oxygen lies far to the right of that of Te.
