The best answer for this question would be to talk to the cashier, in situations like these the customer is always right and knows exactly what they want, and if that doesn't work out ask the manager so he can get the correct coffee he wishes for.
Answer:
1.030-0.545=0.485 grams of oxygen in compound.
Convert grams of Al and grams of O into moles:
0.545g Al x 1 mol Al/26.98g Al = 0.0202 mol Al
0.485g O x 1 mol O/16.00g O = 0.0303 mol O
Next we divide the moles of both of them by the lowest number to get simplest ratio
0.0202/0.0202 = 1 Al
0.0303/0.0202 = 1.5 O
Next we multiply all numbers until we get a whole number for each one. In this case 2 works:
Al 1 x 2 : O 1.5 x 2
and we are left with Al2O3
Explanation:
Hope this helps :D
