1
At its top speed, a cheetah can sprint the length of a football field (100 yards) in 2.73 seconds. What is its speecd in kilometers per hour?
1 yard= 3feet
1foot=12 inch
1inch= 2.54 cm
121
Give the chemical symbols of the three neutral elements in the fourth row of the periodic table that have three unpaired electrons in their ground-state electron configuration.
V, Co, As
An element has the following successive ionization energies, Determine the number of valance electrons for the element.
1st IE- 698
2nd IE- 1378
3rd IE- 1895
4th IE- 2584
5th IE- 14419
6th IE- 18110
4
Match a Molecular Geometry to each of the following...
1) CO2
2) H2CO
3) CH2F2
4) PF5
5) IF5
1) Linear
2) Trigonal Planar
3) Tetrahedral
4) Trigonal Bypyramidal
5) Square pyramidal
A 20.0g sample of an element contains 3.015x10^23 atoms. Find the name of the element
Ar
Calculate the mass of 5.40x10^16 atoms of bismuth, Bi, in ug.
18.7
Gallium has two naturally occuring isotopes: Ga-69 (68.92558 amu) and Ga-71 (70.92470 amu). Find the mass of Ga-71 in a 4.500 g sample of naturally occurring gallium. Give your answer to 3 significant figures.
1.79
Calculate the total number of atoms in 35.8 mg C52H60N11O11.
2.85x10^21
Calculate the mass in grams of iodine in 657mL of 0.341 M calcium iodide solution.
65.8
Calculate the mass of Ca(C2H3O2)2 in ug that contains 5.17x10^16 atoms carbon.
4.12
20.7 grams of H2 and 243 grams of CO are combined according to the reaction below. If 128 Grams of CH3OH are actually produced when the reaction is performed, calculate the percent yield.
77.8 percent
A certain liquid compound is 33.5 percent oxygen by mass. If its density is 0.663g/mL, how many atoms of oxygen are contained in 1.18 L of the compound?
9.86x10^24
A 28.50 g sample of an organic compound containing only carbon, hydrogen, and oxygen undergoes combustion analysis and produces 60.218 g CO2 and 29.581 g H2O. Find the EMPERICAL formula for the organic compound
C5H12O2
21.7 mL of an unknown diprotic acid requires 17mL of a 0.413 M sodium hydroxide to reach the equivalence point during a titration. What is the molarity of the unknown acid solution?
0.167
When light with a wavelength of 363 nm strikes copper, the ejected electrons have 38.0 kJ/mole of kinetic energy. What is the threshold frequency for copper?
7.31x10^14890
What is the sum of the coefficients (including implied 1's) of the net ionic equation for the balanced chemical reaction between aqueous potassium sulfide and aqueous zinc acetate.
5?
The Binding energy of electrons in a metal is 204KJ/mol. Find the threshold frequency of the metal in Hz.
5.11x10^14
You would like to buy a window air conditioner to cool a room with an area of 29 m^2. Window air conditioners are rated in BTU (british thermal units). It is recommened to get an air conditioner with a rating of 24 BTU/ft^2 of the rooms area. What BTU rating will you need for the air conditioner?
HINT- 1ft=12in ; 1in=2.54 cm
7.5x10^3
If 52.2 mL of 0.214 M sodium acetate is added to 63.8 mL of 0.599 M calcium acetate, find the molarity of acetate ions in the final solution.
0.755
Acetone has a density of 0.7857 g/cm^3. How many liters of acetone are in 2.54x10^12 ng acetone.
3.23