Posts by kathleen
Total # Posts: 137
Those are tough questions-to know what is in the mind of the teacher that writes them. Most appear to be metals Tin, Copper, Gold... Perhaps the scientists decided to use Latin names for these. They couln't have 2 C elements (Carbon and Copper) and Co is already Cobalt ...
Latin Name for Gold is Aurum and thus the symbol is Au, not Go as you might expect. Similarly, Lead in Latin is Plumbum so the Symbol is Pb. Copper is Cu, Potassim K. Other symbols were named in other ways. Oxygen is O, Hydrogen H, Sulfur S. Look at your Periodic Table.
Change all the denominators to 12ths. For example, 1/6=2/12 (multiply numerator and denominator by 2) Then you can add all the numerators to get the answer in twelfths. Try it yourself.
You need to multiply 8.00 by 4.5 (hours) EASY!
Thanks-just what I needed.
No 50-2=3m+2-2 48=3m 48/3=3m/3 16=m
Subtract 2 from each side. Then divide each side by 3. You can do it!
5n+15=4n+12 -4n -4n n+15=12 -15 -15 n=-3 Check 5(-3+3)=3(2*-3 +6) 5(0)=3(16+6) 0=3(0) 0=0 4x-4+2x+8 6x+4
There are 1500 ml in 1.5L Sammi said .0015. you multiply 1.5 by 1000 not divide it!
4. Write the balanced equation for CH4+Cl2_CH2Cl2+HCl What are 3 ways you can speed the reaction in this equation?
4. Write the balanced equation for CH4+Cl2_CH2Cl2+HCl6. For the reaction in problem 4, Heat of Reaction = -118.3 kcal/mol. Identify whether this is an exothermic or endothermic reaction. Calculate the Heat of Reaction when 6.00 g of Cl2 are used in the reaction.
Why are fermentation tubes evaluated at 24 and 48 hrs? If an organism oxidatively metabolizes glucose, what will occur in the fermentation tubes?
4. Write the balanced equation for CH4+Cl2_CH2Cl2+HCl 4a. For the reaction in problem 4, ´H = -118.3 kcal/mol. Identify whether this is an exothermic or endothermic reaction. Calculate the ´H when 6.00 g of Cl2 are used in the reaction
8. For the reaction H2(g)+I2(g)\2HI(g); [H2] = 0.95 M; [I2] = 0.78 M; [HI] = 0.27 M. Calculate the equilibrium constant K and describe the direction (forward or reverse) of the reaction. Will adding a catalyst to the reaction alter the direction of the reaction? Why? ...
What are the common molecular shapes around the carbons?
4. Write the balanced equation for CH4+Cl2_CH2Cl2+HCl. 5. Using the equation in problem 4 if 6.00 g of CH4 are mixed with 6.00 g of CL2, how much HCl can be made? What is the percent yield if 2.5 g are recovered from the reaction in the lab?
What is the importance of a freezing point depression graph and why and what things change when different solutes and solvents are added?
The numbers are represented by x, x+1 and X+2. X^2 + (X+1)^2=(X+2)^2 X^2 + X^2 +2X +1=X^2 +4X + 4 2X^2+2X+1=X^2+4X+4 X^2-2X-3=0 (X-3)(X+1)=0 X=3 X=-1 The numbers are X=3, X+1=4 X+2=5 Check: 3^2 + 4^2=5^2 9+16=25 A second solution is X=-1 X=0 X=1 -1^2 + 0^2=1^2 1+0=1
Divide 7 by 12 to get the decimal. 7/12=0.5833 (3 repeating) Multiply by 100 to get percent. 58.33% (3 repeating)
Thanks! So the antifreeze one doesn't have anything to do with vapor pressure?
What colligative properties are displayed by these situations. 1. Antifreeze is added to car cooling system preventing freezing when air temp is below 0 degrees C. 2. Ice melts on sidewalk after salt has been spread
X^-6 times X^5= X^-1 (add exponents -6 + 5=-1 X to the negative 1 can be rewritten 1/X so you have only postitve exponents. Y^-12 divided by Y^5 = Y^-17 (subtract exponents -12-5=-17) So Y^-17=1/Y^17
The half life of carbon 14 is 5700 years. So If a fossil is 5700 years old then half of the carbon-14 is left.
what is the solution to 2(-5y cubed)squared + (-3ycubed)cubed
#. additional space for children could provide in classoom 3 with the additional of A. a closet B. counters and storage underneath c.cubbies D. a loft
Why does the President as commander-in-chief of the armed forces?
What is one animal that lives in the rainforest and what is it's adaptation?
I guess I'm missing something here...but I've approached this question in every possible angle and im just not getting it! Could somebody point me in the right direction? Here is the question: If the measured net radiation (Q*) for the lawn of your home in August is ...
what is faster panther or cardinal
Umm... Maybe: She's going to buy him a present, but can't decide what to get him. Maybe something along those lines? I don't know if that works or not.
Divide: 4 1/5 / 14
if 3ãx6 + 3ã8x3 + 3ã1 = 0, then x= (A) -1 (B) 0 (C) 1 (D) 2 (E) 3
name each ion 1. As3- 2. Ca2+ 3. H- Since this is not my area of expertise, I searched Google under the key words "H- ion", As3- ion" (Sure you don't mean "+"?) and Ca2+ ion" to get these possible sources: http://www.h-minus-ion.org/ http://...
5th Grade Math
I cannot get my brain around questions like this: 1/4 divided by 2/5 = 2/4 x ? I have 4 problems like this and even the example doesn't make sense - I may have copied it wrong off of the board. Can anyone help? Thank you! You invert the second fraction and then just ...