If I needed to convert from mass to mol, I would use the ________ from the __________.
What is molar mass from the periodic table
100
An element is determined by the number of ________ that it has.
What is protons
100
The simplest ratio between elements is also known as the...
What is empirical formula
200
What are the units for mass, volume, and length?
What is Gram, Liter, Meter
200
T/F, leading zeros and zeros between non-zero digits are significant.
What is false- only zeros between non-zero digits are significant, not leading zeros.
200
If I wanted to go from # of molecules to moles, I would use ___________.
What is Avogadro's Number (6.022e23)
200
The atomic mass is the sum of what?
What are protons and neutrons
200
How does one solve for molecular formula knowing molecular mass and empirical formula?
Molecular Formula Mass/ Empirical Formula Mass to find n.
Multiply n by Empirical Formula.
300
What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3?
What is .850g/cm^3
300
How many significant digits are in the following answer:
0002.03200/.000340=
What is 3 sig figs. The correct answer is 5.98e3.
300
Given the following reaction:
Zn+2HCl→ZnCl2+H2
How many moles of ZnCl2 will be produced from 55.0 g Zn, assuming HCl is available in excess?
What is .841mol
300
Electrons are always equal to the number of protons unless there is a distinct _____. A positive ____ means that you _____ electrons. A negative charge means that you ______ electrons.
Charge
Charge
Lost
Gained
300
What is the rhyme that we use to remember how to solve for empirical formula?
% to mass
Mass to mol
Divide by small
Multiply 'till whole
400
Iron Ore weighing 81g was placed in a flask whose volume was 50g. The flask was filled with water and weighed. The mass of the ore and the water was 120g. What was the density of the ore? (dH2O=.997g/mL)
What is 7.4g/mL
400
When multiplying and dividing, you look at ____ to determine sigfigs.
What is number of significant figures.
400
How many moles of chlorine gas (Cl2) would react with 5.0 moles of sodium (Na) according
to the following chemical equation? (Balance equation.)
Na + Cl2 --> NaCl
What is 2.5mol Cl2
400
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
What is isotope
400
Find Empirical Formula:
C: 64.3%
H: 7.2%
O: 28.5%
What is C3H4O
500
Which one weighs more, a mol of bricks or a mol of feathers? Why?
What is mol of bricks.
500
When adding and subtracting, you look at _____ to determine significant figures.
What is number of places after the decimal
500
C4H10+O2 -> CO2 + H2O
1) Balance the equation
2)If we had 203mg of C4H10, how many molecules of CO2 could be produced assuming an excess of O2?
1) 2C4H10+13O2 -> 8CO2 + 10H2O
2) 8.41e21molec
500
The molar mass is determined by...
Weighing 6.022e23 atoms of an element.
500
Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. What is its molecular formula?