Some answers:

question  3 (b) - simply work out the two quantities of heat and add them together:

Q = m_copper x c_copper x Dq   +   m_water x c_water x Dq

  =  20        x    390     x 1      +    70     x  4200  x 1

question 4  -  rearrange Q = m_copper x c_copper x Dq

                                     Dq =      Q             but  Q = ItV   (see module 3)
                                                m   c

                                                                  remember   t = 60s

question 11     P₁  V₁         =        P₂   V₂     temp is constant - so cancel it out
                          T₁                          T₂

  1.5  x  10⁶  x   5 x 10^-2   =    2.0 x 10⁶    x   V₂

rearrange to find V₂

question12  

pV = nRT    where  R = 8.31JK^-1mol^-1      rearrange to find n

n   =   pV    =    1 x 10⁶  x  3 x 10^-3
          RT             8.31    x    327

number of atoms - makes use of the Avogadro Constant

    1 mole contains 6x 10^-23 atoms
so n moles contains n x 6x 10^-23 atoms

volume vs temp description: