1. 9.5g of magnesium chloride reacts with 8.0g of sodium hydroxide to form 5.8g of magnesium hydroxide. a) calculate the mass of sodium chloride produced
b) use the masses to calculate the moles of each substance, as the simplest whole number ratio. balance the equation below:
MgCL2 + NaOH ---> Mg(OH)2 + NaCL

Caso4(s) < > ca+2 + so4^-2 ksp = [ca+2][so4^-2] = 2.4 x 10^-5 = [0.20][so4^-2] [so4^-2] =1.2 x 10^-4 ag2so4(s) ,> 2ag+ + so4^-2 ksp = [ag+]^2[so4^-2] = 1.5 x 10^-5 = (0.30)^2[so4^-2] [so4^-2] = 1.5 x 10^-5/0.09 = 1.7 x 10^-4 caso4 would precipitate first since it requires less so4^- to form a saturated solution.  i believe this is right, i hope it !  

Most elements have more than one naturally occurring isotope. as you learned previously, the atoms of those isotopes have the same atomic number (number of protons), making them belong to the same element, but they have different mass numbers (total number of protons and neutrons) giving them different atomic masses. so which mass is put on the periodic table for each element? is it the most common isotope’s mass? the heaviest mass? this activity will answer that question.