Exo and Endothermic Rxns
In an experiment the temperature changes from 30 Celsius to 10 Celsius. That means the reaction is...
Endothermic
Which is the symbol used in an equation to represent an alpha decay, beta decay and gamma decay.
(write them in that order)
4/2 He
0/-1 e
0/0 gamma
If the H+ concentration is 0.0001, what is the pH?
Would it be an acid or base?
pH = -log (0.0001)
pH= 4 (Acid)
Which are the 3 methods of heat transfer?
conduction, convection and radiation
True or False. Hot Hands (hand warmers) are an example of an endothermic reaction.
False, they are an example of exothermic reaction.
What is the change in atomic mass when an atom emits gamma radiation?
A. remains the same
B. Decreases by 2
C. Increases by 1
A. Remains the same
True or False. Bases turn litmus paper blue and taste sour.
False! B,B,B
Bases turn litmus paper blue and taste bitter.
The transfer of heat within an object or between objects that are in direct contact with each other is ....
conduction
If the temperature decreases (goes down), then you know it is an ___________ reaction.
Endothermic
Nuclear reactions involve the ____ while chemical reactions involve _____.
Choose from the words below:
electrons, nucleus, protons, neutrons
Nuclear reactions involve the nucleus while chemical reactions involve electrons.
If the pOH of a solution is 8.7, would this be an acid or a base? Explain your answer.
An acid because pH = 14-pOH
pH= 14-8.7 = 5.3
The transfer of heat due to movement within a liquid or gas because of density changes is
convection
When the enthalpy of the reaction is positive the reaction is ______ and when is negative the reaction is ___________.
endothermic, exothermic
Which type of decay would complete the following reaction?
22284Rn --> 21882Po + ____
Alpha 42He
If a solution had a pOH of 12.3, would this be considered an acid or a base ? Explain why.
Acid because pH= 14-pOH
14-12.3= 1.7 so Acid
A lava lamp works due to this method of heat transfer.
convection
Label the following graphs as endothermic or exothermic.
Label from left to right.
Left: Exothermic
Right: Endothermic
Which option would complete the following decay
23490Th --> _____ + 0-1e
A. 23489Pa
B. 23491Bi
C. 23490Th
B. 23491Bi
If the pH of a solution is 1.1, what does this say about the H+ concentration?
A. its very high
B. its very low
C. its neutral
A, its very high. The closer to 0 (strong acid) the higher the H concentration.
Feeling the warmth from a campfire is an example of
Radiation