An element has two isotopes. Calculate the (weighted) average atomic mass using the following data.% abundance     mass                                                                                               72.172%            84.9117897 amu              mass contribution is __1__ amu27.832%            86.9091805 amu              mass contribution is __2__ amu The average atomic mass is __3__ amu.A.  84.9117897       B.  86.9091805        C.  85.471        D.  61.282537E.  24.188563         F.  6128.2537         G.  2418.8563         H.  8547.1I.  answer not provided _______ _______ _______

Convert a temperature of -110.00 oF into Celsius.  oF = 1.8 oC  +  32The final answer is numerically __1__ and the units are oC.A.  -93.111          B.  -43.333         C.  43.333           D.  93.111          E.  -255.600F.  140.400          G.  -140.400       H.  -78.889         I.  78.889            J.  255.600 _______

How many m in 5.10 x 109 inches ?  Use 2.54 cm = 1 in.  Note, this is set up as a two-step problem.The intermediate answer is numerically __1__ and the units are __2__ .The final answer is numerically __3__ and the units are __4__ .A.  5.10 x 109            B.  1.30 x 108            C.  1.30 x 109            D.  1.30 x 1010E.  2.01 x 109               F.  2.01 x 108            G.  2.01 x 1010           H.  2.01 x 109I.  in         J.  cm           K.  m         L.  km _______ _______ _______ _______

The mass of a single carbon-12 atom in amu is __1__ amu.Given that 1 amu = 1.6606 x 10-24 g, the mass in grams of a single carbon-12 atom is __2__ g.A.  12.0107      B.  12.0000      C.   1.9927 x 10-23      D.  7.2263 x 1024E.  1.3838 x 10-25             F.  1.3826 x 10-25                G.  1.9945 x 10-23H.  answer not provided _______ _______

A serving of Skippy Superchunk Peanut Butter (32.00 g) contains 16.00 g of fat, 7.00 g of carbohydrate, and 7.00 g of protein.Calculate the Cal per serving.  Fat contains 9.00 Cal/g, and carbohydrate and protein both contain 4.00 Cal/g.The Cal from fat is __1__ CalThe Cal from carbohydrates is __2__ CalThe Cal from protein is __3__ CalThe total Cal is __4__ CalA.  144           B.  200.           C.  28.0            D.  64.0            E.  172         F.  56.0           G.  170           H.  answer not provided _______ _______ _______ _______

How many grams in 2.111 x 106 mL of iron if the density is 7.874 g/cm3 ?The final answer is numerically __1__ and the units are __2__ .A.  2.111 x 106             B.  1.662 x 104           C.  1.662 x 107             D.  1.662 x 1010 E.  2.681 x 105              F.  2.681 x 108           G.  2.681 x 102          H.  g            I.  mLJ.  cm3           K.  cm _______ _______

Determine whether the ordered pair (6, -6) is a solution to the system of linear equations below. Show your work on the sheet provided for full credit. x – y = 12                          y = 32 – 6x

What will be the pH if 0.00150 moles of HCl is added to 1.00 L of water ? The reaction gives the conversion factor                  HCl    +     H2O    →      H3O+1     +     Cl-1 start:  0.001500                                 0                   0 equil:          0                                –––––––       –––––––

A large Keq indicates that a lot of products are formed

Buffers work best when [HA] = [A-1]