Answer: Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change.
...."heavier". *The definition of radioactive decay shall do its explanation.
Answer:
x = 100 * 1.1897 = 118.97 %, which is > 100 meaning that all of the HClO2 dissociates
Explanation:
Recall that , depression present in freezing point is calculated with the formulae = solute particles Molarity x KF
0.3473 = m * 1.86
Solving, m = 0.187 m
Moles of HClO2 = mass / molar mass = 5.85 / 68.5 = 0.0854 mol
Molality = moles / mass of water in kg = 0.0854 / 1 = 0.0854 m
Initial molality
Assuming that a % x of the solute dissociates, we have the ICE table:
HClO2 H+ + ClO2-
initial concentration: 0.0854 0 0
final concentration: 0.0854(1-x/100) 0.0854x/100 0.0854x / 100
We see that sum of molality of equilibrium mixture = freezing point molality
0.0854( 1 - x/100 + x/100 + x/100) = 0.187
2.1897 = 1 + x / 100
x = 100 * 1.1897 = 118.97 %, which is > 100 meaning that all of the HClO2 dissociates
Initially, you should know that what the text describes is a test used to analyze and identify some metal ions in a compound. This is the principle behind it: first the ions are excited, by the heat of the flame, they absorb energy and the electrons are promoted to higher energy levels; after this, the electrons will fall back down to lower energy levels releasing energy as light. The flame color that is seen is related with the frequency of the light emitted.
Here is the text with the right words.
In this experiment, the metal cations in the solutions were initially in
the ground state. When placed in the flame, the metals then (absorbed)
energy as (heat). When this occurred,
electrons made transitions from (low) energy levels to (high)
energy levels. The metals were then in the (excited) state. The
electrons in these metals then made transitions from (high) energy
levels to (low) energy levels, resulting in the (emission) of energy as (EM radiation).
