Intro to Chem
Chemistry is defined as
Chemistry is defined as the study of matter and energy
What is the most common solution?
The most common solution is an aqueous solution (water solution).
True or False Non zero numbers are sometimes significant.
False they are are always significant.
The molecule drawn on the board is in what state of matter?
solid
what is the equation for density?
D=m/v
How many elements are on the periodic table?
118
What is a solution?
A solution is a homogeneous mixture. A solution is made by dissolving a solute in a solvent.
Is the diagram on the board accurate, precise, both, or none?
accurate but not precise
What is the difference between extensive and intensive properties of matter?
Extensive Property: a property that depends on the amount of matter in a sample
ie; amount of substance, energy, enthalpy, Gibbs energy
Intensive Property: is a property that depends only on the type of matter not the amount.
ie; color, temperature, soluability
what do the following unit measurements stand for g, m, L?
grams, meters, Liters
Scientists use a systematic approach to solve problems called.....
The scientific method
What is the equation for % by volume?
% volume = Vsolute/Vtotal
0.14+1.2243
1.36
A physical change occurs when matter changes from one form to another, without changing its chemical composition.
solid, liquid, gas, sometimes plasma
3 days is equal to how many seconds?
259200 s
How are hypothesis written?
In an "if , then" statement
How many liters of salt solution would be needed to provide 30g of salt if the concentration of the solution is 20g/L?
20=30/x =1.5L
What is precision?
Precision is a measure of how close a series of measurements are to one another
What is an Amorphous solid and give an example?
“without form” solids, such as glass and plastics, lack a definite crystalline structure.
Mercury metal is poured into a graduated cylinder that holds exactly 22.5 mL. The mercury used to fill the cylinder weighs 306.0 g. From this information, calculate the density of mercury.
d=13.6 g/mL
What is organic chemistry? And what are organic chemists responsible for?
The study of compounds that contain carbon and hydrogen.
-Organic chemists are responsible for the production of pharmaceuticals, petroleum products, plastics, and many food-related products
Joshua uses his thermometer and finds the boiling point of ethyl alcohol to be 75o C. He looks in a reference book and finds that the actual boiling point of ethyl alcohol is 80oC. What is his percent error?
(75-80)/80 = .0625 X 100 = 6.25%
(1.23)(3.467)/3.96
1.08
What are chemical properties of matter?
flammability, reactivity, combustibility, acidic or basic, tendency to ionize in solution, electronegativity
5.67g/mL= lbs/L
12.5 lbs/L