##### Chemistry test 23-32

 Chemistry Tutor: None Selected Time limit: 1 Day

Mar 3rd, 2015

23 ). Pb(C3h2O2)4 moleculer weight is 1165 grams

so here we have 12 carbon atoms and each of it weighs 12

so number of moles= 1165/12*12=8 (OPTION A)

24).

A) 2  (the coffient will be 2 after balancing)

25).

D option is balanced

since 2H2O --> 2H2 + O2

this equation  also release energy and 4H AND 2O

26)

molar mass of Ca(NO3)2 = 164 (Option D)

Ca = 40 +(14.0 +15.9*2)3=164.1 (40 weight of Ca and for N=14 and O=15.9)

27).

greater molar mass is Br2 =2*79.99 = 159.808 ( Option C)

for C2H4= 28

CF4=88

CO=28

28) to produce 1 mole of Cu we need 128 grams of iron (A Option)

29). the balanced equation is

2 H3PO4  + 3 Mg(OH)2  ----> 1 Mg3(PO4)2 + 6 H2O

SO  (2, 3, 1 , 6) ->Option A

30).For 4 NH3 WE require 5 O2

then for 2 NH3  we require  5/2 = 2.5 -->(Option C)

31). C) 12 grams

32).

formule

K= 273 + C

473 = 273 +c
c= 200 -->(option C)

Jun 13th, 2015

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Mar 3rd, 2015
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Mar 3rd, 2015
Dec 4th, 2016
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