Wednesday
May 22, 2013

# Posts by Alan

Total # Posts: 278

math
x+8y=33 ---- (1) -x+4y=3 ---- (2) (1) + (2), x + 8y + (-x + 4y) = 33 + 3 12y = 36 y = 3 sub y = 3 into (2), -x + 4(3) = 3 -x = 3 - 12 -x = -9 x = 9 CHECK: sub x = 9 and y = 3 into (1), 9 + 8(3) = 33

math
6m+n=47 --- (1) m-4n=12 --- (2) From (2), m = 12 + 4n --- (3) sub (3) into (1), 6(12 + 4n) + n = 47 72 + 24n + n = 47 25n = -25 n = -1 sub n = -1 into (3), m = 12 + 4(-1) m = 8 CHECK: sub m = 8 and n = -1 into (2), 8 - 4(-1) = 12

Chemistry
Copper(I) Iodide is synthesised by the equation: 2CuSO4.5H2O + 2KI + 2Na2S2O3.5H2O --> 2CuI + K2SO4 + Na2SO4 + Na2S4O6 + 10H2O Would it make a difference if anhydrous CuSO4 and Na2S2O3 are used instead? Why hydrous CuSO4 and Na2S2O3 are used instead?

Chemistry
What is the stoichiometric ratio for Cu2+ ions with cuprizone to form the copper-cuprizone complex?

Chemistry
How should I write the balanced chemical equation to represent the oxidation of Cu+ ion by air? [Cu(NH3)3]^+1 + 2H2O + ??? --> [Cu(NH3)3(H2O)2]^+2

Chemistry
Can [Cu(NH3)2]^+ and/or [Cu(NH3)3]^+ be oxidised by air to become [Cu(NH3)2]^2+ and [Cu(NH3)3]^2+ respectively?

Chemistry
What would be the most likely product(s) when you react CuI with NH4OH?

Chemistry
What is the chemical equation for: CuI + NH4OH ---> ??? This equation should oxidise Cu+ to Cu2+.

Physics Tough question!
o wow, i didnt even think of the geometrical way, thanks.

Physics Tough question!
A pond has the shape of an ice cream cone with the tip slices off and has a depth of 5.00m. The atmospheric pressure above the pond is 1.01 *10^5 Pa. The circular top surface (radius = R2) and circular bottum (radis = R1) of the pond are both parrallel to the ground. The angle...

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