how do i calculate
1) number of moles for 3.01 times 10 to the power of 24
2)number of atoms of formula units in 7.5 moles of potassium bromide (KBr)
2007-07-09 22:18:53 · 2 answers · asked by ping 1 in Science & Mathematics ➔ Chemistry
1) Divide by Avogadro's number, which is 6.02×10^23, to get 5.00 moles.
2) This isn't really clear; do you want the number of atoms or the number of formula units? There are 7.5 × 6.02×10^23 = 4.5×10^24 formula units, and twice as many (9.0×10^24) atoms.
(Note: One formula unit consists of one atom each of K and Br, so there are two atoms per formula unit. If it was something like CaCO3, there would be five atoms per formula unit.)
2007-07-09 22:28:48 · answer #1 · answered by Scarlet Manuka 7 · 0⤊ 0⤋
one mole of each substance contains its 6.022*10(23) particles. 3.01*10(24)/6.022*10(23)= X will be the number of moles and 7.5*6.022*10(23)*2= atoms in 7.5 moles of KBr.
2007-07-10 05:29:41 · answer #2 · answered by usman a 1 · 0⤊ 0⤋