Answer:
70mol
Explanation:
The equation of the reaction is given as:
2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
Given parameters:
Number of moles of acetylene = 35.0mol
Number of moles of oxygen in the tank = 84.0mol
Unknown:
Number of moles of CO₂ produced = 35.0mol
Solution:
From the information given about the reaction, we know that the reactant that limits this combustion process is acetylene. Oxygen is given in excess and we don't know the number of moles of this gas that was used up. We know for sure that all the moles of acetylene provided was used to furnish the burning procedure.
To determine the number of moles of CO₂ produced, we use the stoichiometric relationship between the known acetylene and the CO₂ produced from the balanced chemical equation:
From the equation:
2 moles of acetylene produced 4 moles of CO₂
∴ 35.0 mol of acetylene would produced:
= 70mol
Answer:
B. Coal
Explanation: Coal is mined to produce energy.
A. phase changing. Physical change is any change in matter that involves the substance going from one physical state to another, and phase change is most commonly used to describe transitions between solid, liquid and gaseous states of matter.
Number of photons can be calculated by dividing the needed energy by the energy per photon.
The minimum energy needed is given as 2 x 10^-17 joules
Energy per photon = hc / lambda where h is planck's constant, c is the speed of light and lambda is the wavelength
Energy per photon = (<span>6.626 x 10^-34 x 3 x 10^8) / (475 x 10^-9)
= 4.18 x 10^-19 J
number of photons = (2 x 10^-17) / (4.18 x 10^-19)
= 47.79 photons which is approximately 48 photons</span>
Oxygen
For metals, reactivity increases as we move through the elements in the period table from top to bottom, and left to right. In contrast, for nonmetals, reactivity increases as we move through the elements in the periodic table, as we move from bottom to the top, and right to left.
Group 16 on the periodic table is also called the oxygen family or chalcogens. It includes the following elements from top to bottom: Oxygen, Sulfur, Selenium, Tellurium, and Polonium. Of these, only Oxygen, Sulfur, and Selenium are nonmetals. Since reactivity of nonmetals increases going up the periodic table, oxygen is therefore the most reactive nonmetal in the group. Shown in the figure below is the reactivity trend in the periodic table.
