So what you’re going to do is basically the + and - in each top hand corner is the charge of compound, so for example Li has a charge of +1 while Br has a charge of -1 , to write the formula you need to get the charges to cancel out ( equal zero) so luckily this was easy because -1 +1 =0 ! So it would be LiBr. Though for another example Al has a charge of 3+ while br has a charge of -1 and these do not equal zero, so as a result you have to add more br making the Formula AlBr3! Hope this helps!
Answer:
5 mL
Explanation:
Given data:
mass of ring = 107 g
volume of water = 10 mL
increase in volume = 15 mL
How much water displace = ?
Solution:
V (ring) = V (water + ring) - V (water)
V (ring) = 15 mL - 10 mL
V (ring) = 5 mL
when the ring is put into cylinder, volume is increased by 15 mL. The volume of water was 10 mL so water is displaced by 5 mL and the volume 5mL is the voulme of ring.
Answer:
44 g oxygen are needed.
Explanation:
Given data:
Mass of oxygen needed = ?
Mass of ammonia = 18.2 g
Solution:
Chemical equation:
4NH₃ + 5O₂ → 4NO + 6H₂O
Now we will calculate the number of moles of ammonia:
Number of moles = mass/molar mass
Number of moles = 18.2 g/ 17 g/mol
Number of moles = 1.1 mol
Now we will compare the moles of ammonia with oxygen from balance chemical equation.
NH₃ : O₂
4 : 5
1.1 : 5/4×1.1 = 1.375 mol
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 1.375 mol × 32 g/mol
Mass = 44 g
