20 Which of the following is an unbalanced equation?*
(1 Point)
a. CaCO3 --> CaO + CO2
O b. 2PbO 2 + 2H 2 -->2Pb +2H2O
O c. 2Na+ 2H 2 O-->2NASH + H 2
d. CS 2 + 20 2 --> CO 2 + 250 2

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml