Answer:
1.8×10^-2mm or 0.018mm
Explanation:
Density = mass/Volume
But volume= area×thickness
Area= 50ft2= 46451.52cm2
Mass=8oz= 226.7962g
Density= 2.70g/cm3
Thickness= mass/density ×area
= 226.7962/46451.52×2.70= 1.8×10-3cm= 1.8×10^-2mm
First find the no. of moles of NaOH :
<span>30/1000 = 0.3 dm3 so no. of moles = 0.3*0.5 = 0.15 moles </span>
<span>as NaOH reacts with HNO3 in a ratio of one to one, there must have been 0.15 moles of HNO3 too </span>
<span>moles/volume = concentration </span>
<span>volume= 15/1000 = 0.15 dm3 </span>
<span>concentration = 1.15/0.15 = 1 mol.dm-3 </span>
<span>The quicker way would be to realize that you used twice as much NaOH so the HNO3 had to be twice as strong</span>
5 atoms is in 2CaCO3
Element: 1 atom
Compounds: 2+ atoms