Answer:
Molar mass Na2CO3 = 2*23 + 12 + 3*16 = 106 g/ mol
Mass of 1 mol Na2CO3 = 106 g
mass (Na2CO3) = 106g*250cm³/1000cm³ = 26.5 g
1) It is necessary because all Na2CO3 will be in the solution, and no Na2CO3 would be lost.
2) Because the solution that was formed after rinsing beaker contains Na2CO3.
3) Eyes should be on the level of calibration mark of the volumetric flask.
4) It is necessary to prevent evaporation of water, and changing , because of it, the concentration of the solution.
In the periodic table, there are seven horizontal rows of elements called periods.
Protons are heavy particles. Electrons are far from a nucleus. So your choice is <span>4. protons; electrons.</span>
To solve for moles use molar and volume:
M = mol/L
0.02700 m= mol/(.75 L)
mol = .036 mol of Hg(NO3)2
The proportion of Hg(NO3)2 to the Mercury that is used to create
HgS is 1:1 so solve for the moles of Mercury used. So:
.036 * (1 Hg(NO3)2 / 1 Hg) = .036 moles of Hg used to make
HgS
The proportion of Mercury to HgS is 1:1, as an alternative
of doing the obvious math you can conclude that .036 moles of HgS will be
produced because you're given .036 moles of Hg and an excess of S. Use the
molar mass of HgS to determine how many grams will be produced.
.036 moles * 232.66 g/mol = 8.37576 grams of Vermilion is
produced.
