physical & chemical changes
Rotting food and fizzing are signs of what kind of reaction? AND how do you know?
Chemical: color change, sound produced, gas produced
Convert 34.5 moles of Carbon to mass of carbon
34.5 mol x 12.011g/mol = 414.38 grams
OR
34.5 mol x 12g/mol = 414 grams
Would you rather have a head the size of an orange or the size of a watermelon?
Orange: +200
Watermelon: -100
What was the first vegetable ever to be grown in space? Hint: not green!
potato!
How many electron shells does Magnesium have?
Mg is in Period 3, which means it has 3 electron shells
In what fictional Indiana town does the sci-fi series “Stranger Things”
Hawkins
What is greatest in mass: 23.5 moles of aluminum, 15.7 moles of titanium, or 11.7 moles of copper?
23.5 mol Al = 632.15 g
15.7 mol Ti = 750 g
11.7 mol Cu = 742.9 g
How many neutrons does Chlorine have?
Neutrons = Mass - Protons
35g/mol - 17 = 18 Neutrons
Balance:
N2 + H2 --> NH3
N2 + 3H2 --> 2NH3
What are 3 metalloids?
Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium
Chemical or Physical?
KNO3(s) --> K+(aq) + NO3-(aq)
Physical -- it dissolved
What actor plays Ken in the 2023 blockbuster movie “Barbie?”
Ryan Gosling
What's the name of the pig in the book “Charlotte's Web”?
Wilbur
When ionic compounds are added to water, they dissolve. This is a physical change. If you were to read a chemical equation on paper, what would you see that tells you a compound has dissolved?
The symbol would be (aq), which stands for aqueous
NaCl(s) + H2O(L) = Na(aq) + Cl(aq) + H2O(L)
What are two properties of the elements in group 17?
1) Nonmetals
2) Highly reactive
3) Have 7 valence electrons
4) High electronegative (meaning they like to steal electrons from others)
CH4(g) + 2O2 --> CO2(g) + 2H2O(g) + 245KJ
Chemical or physical? What does KJ stand for and what does it tell you?
Chemical, KJ = kilojoules, which tells you the reaction releases heat
2Fe + 3H2SO4 --> 1Fe2(SO4)3 + 3H2
If 3.5 moles of Iron Sulfate were produced, how many moles of Sulfuric Acid did you start with?
3.5 x 3/1 ratio = 10.5 mol H2SO4
Nitrogen has the electron configuration 1s22s22p3. What is the electron configuration for sodium?
1s22s22p63s1
State this equation aloud:
AgI + Na2S --> Ag2S + NaI
Silver Iodide + Sodium Sulfide --> Silver Sulfide + Sodium Iodide
The classic 1877 novel “Black Beauty” is about what kind of animal?
a Horse
A group of chemistry students were conducting a lab to investigate the the change that takes place when potassium chlorate (KClO3) gets heated and decomposes. They noticed that when the reaction is completed, the mass of the products have decreased. What do you think causes this decreased mass? Extra 300 pts if you can name the products!
KClO3 decomposes into KCl and O2. Because a gas is formed, the mass on the scale has decreased as the oxygen has escaped into the air.
2Fe + 3H2SO4--> 1Fe2(SO4)3 + 3H2
This reaction started with 10g Fe. How many grams of H2 were released?
10g Fe x 1mol/55.85g = 0.179 mol Fe
0.179 x 3/2 (ratio) = 0.269 mol H2
0.269 mol H2 x 2g/1mol = 0.537g H2
What is the formula for ammonium sulfate?
(NH4)2SO4
NH4 has a +1 charge and SO4 has a -2 charge
Write and balance the equation:
Iron (III) Oxide + Carbon(s) --> Fe(s) + CO2
2Fe2O3 + 3C --> 4Fe + 3CO2
Why are Group 17 and Group 1 elements highly reactive?