Answer:
the second one looks like it so I picked the second one
Answer:
The answer to your question is 0.269 g of Pb
Explanation:
Data
Lead solution = 0.000013 M
Volume = 100 L
mass = 0.269 g
atomic mass Pb = 207.2 g
Chemical reaction
2Pb(s) + O₂(aq) + 4H⁺(aq) → 2H₂O(l) + 2Pb₂⁺(aq)
Process
1.- Calculate the mass of Pb in solution
Formula
Molarity = 
Solve for number of moles
Number of moles = Volume x Molarity
Substitution
Number of moles = 100 x 0.000013
Number of moles = 0.0013
2.- Calculate the mass of Pb formed.
207.2 g of Pb ----------------- 1 mol
x g ----------------- 0.0013 moles
x = (0.0013 x 207.2) / 1
x = 0.269 g of Pb
The answer should be:
KOH (aq) + HCl (aq) --> KCl (aq) + H20 (l).
KOH is a base, because OH can accept a H+.
HCl is an acid because it can donate a H+.
In general, bases are : OH-, and acids are : H+.
Answer: The density of the object will be 
Explanation:
Density is defined as the mass contained per unit volume.
Given : Mass of object = 19.6 grams
Volume of object= 
Putting in the values we get:
Thus density of the object will be
Explanation:
Hardness test — Scratch the rock with a fingernail, a copper penny, a glass plate or nail, and a ceramic plate. Check your Guide to assign it a rating on the Mohs Scale of Hardness.
Color streak test — Test for the “color streak” of the minerals by rubbing the rock across the ceramic plate in the Mineral Test Kit, or across smooth
cement. Look up which colors indicate which minerals are present.
Magnetism test — Hold the magnet in the Mineral Test Kit near your rock. If there is a magnetic pull, it has a metal mineral in it.
Acidity test — Put vinegar in the bottle included in the Mineral Test Kit. Squeeze out a few drops on the rock. If it fizzes, it contains carbonate.
A quick and easy way to find out whether your diamond is real or fake: try fogging it up with your breath. If it clears up after one or two seconds, then your diamond is real, but if it stays fogged for three to four seconds chances are that you're looking at a fake.
