Recent content by geffman1

A solution which is formed by combining 200. mL of 0.15 M HCl with 300. mL of 0.090 M NaOH has a pH of ____ ive worked out concentration of H ion is 0.03 and the concentration of OH ions 0.027. but i don't know what to next? answer is 2.2 thanks

hey, umm yep? I am confused

thanks, but how do u no you have to use the coeffecient of the oxygen, when the Ba is limiting?

hey mate i checked with the teacher and ur right(stupid internet tests). just wondering if you could show me where you got a few of the those numbers from, I've tried but get lost. thanks

Homework Statement We examine the conversion of cyclopropane to propene, a first order process. If we begin with 0.0200 M cyclopropane and find that after 168 s the concentration of propene is 0.00286 M, what is the rate constant, k, at this temperature? i used the...

dw, I am stupit. thanks mate

ta, how do i work out how much is produced?

We examine the reaction A B which displays first-order kinetics. We know that k = 0.30 / min. If we begin with [A] = 0.54 M what will [B] be after exactly 7.00 minutes? hey i used the formula In[A]/[Ao]=-kt then rearranged to In[A]=-kt+[InAo] when i sub it in i get...

The value of H° for the reaction below is -1107 kJ: 2Ba(s) + O2(g) --> 2BaO(s) How many kJ of heat are released when 5.75 g of Ba(s) reacts completely with oxygen fo form BaO(s)? i worked out the moles of Ba which was 0.0412 then times by -1107 whcih is 46.4 however the answer is...

o soz that * is not a multiple sign its the conjurate sign i think. o yeh the bottom should be (6-2i)-(3+9i)=3+7i. is that right??

hey guys I've got a problem If z = 3− i and w = 1+3i, evaluate Im (z∗w)/(2z − 3w) my attempt... ill do top first (3+i)(1+3i)=3+9i+i+3i^2=10i? bottom=3-2i-3+9i=7i therefore answer equals 10/7 however answer is 3/13. could someone please help. thanks

hey guys just had a test, i got a trig proof prob with cot 3u, just wondering how u break it up. thanks

wow i think it just clicked, since HCOOH is weak, can we ignored it and just use the concentration of NO3 because its strong. because that works out. if that is right u just saved me so much time. thanksss heaps

i am confused haha, could u show me ur working for the dissocaition working please, if it is a weak acid isn't that's y the give the ka value for it. so does this just mean i used the dissociation expression for HCOOH and just used -log for HNO3? thansk

does that mean just make the dissocation equation just with HNO3. well this is what i did. HNO3>NO3 + H therefore equation equals. [H][NO3]/[HNO3]=1.8e-4 therefore solving this x^2/0.1=1.8e-4 therefore i get a ph of 2.37? thansk for replying