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Why can’t we notice quantization of energy in our daily events/ activities?
Ultraviolet light with a wavelength longer than about 295 nm has little germicidal value. What is the frequency (in Hz) that corresponds to this wavelength?
Using the equation and the value of the speed of light constant identified in the previous parts, solve for the frequency, in Hertz, of a wavelength of 295 nm
What is the energy of the radiation emitted when an electron in a hydrogen drops from an energy level of n high = 6 to n low = 4. Enter answer in the form 1.00 E2
When copper is placed in silver nitrate a single displacement reaction occurs, producing solid silver as one of the products. When a group of students carried out this reaction they calculated that 2.50 g of solid silver should be produced given the amounts of the reagents they used. However, they were only able to isolate 2.13 g of silver. What is the percent yield for this reaction?
Q8. What is the wavelength of spectral line resulted from the electron transition from n=3
to n=1 in a hydrogen atom?
Q7. A gas mixture that has the following composition in percent by volume: 10.2% CO2,
21.0% CO, 18.5% H2, 2.3% CH4 and 48.0% N2.
(a) What is the density of this gas at 24 °C and 755 mmHg, in grams per liter?
(b) What is the partial pressure of CO in this mixture at STP?
(c) What volume of air is required for the complete combustion of this mixture of gas? (Air
contains 21% O2 by volume)
An experiment is conducted in two steps. In step 1, a black solid compound is heated in a test
tube. The reaction produces a colourless gas that re-lights a glowing splint. Remaining in the
bottom of the test tube is a reddish-brown coloured solid metal. In step 2, the metal resulting
from step 1 is added to a tube of hydrochloric acid, and no reaction is observed.
a. Name the gas produced in step 1.
b. What type of reaction occurred in step 1? Provide a piece of evidence from the experiment
to support your answer.
Write the complete equation of the chemical reaction that occurred in step 1 only. Include
state symbols. Assume the cation in the reactants has the higher of its two possible charges.
The reaction between solid aluminum and liquid bromine is exothermic. This reaction creates the product aluminum bromide.
What equation includes the correct formulas and demonstrates conservation of mass?
What is the mass in grams of CuO that would be required to produce 86.00 moles of nitrogen gas in the following chemical reaction?
2 NH₃(g) + 3 CuO(s) → 3 Cu(s) + N₂(g) + 3 H₂O(g)
