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.
Answer:
C:
Explanation:
March 22, 1868 – December 19, 1953) was an American experimental physicist honored with the Nobel Prize for Physics in 1923 for the measurement of the elementary electric charge and for his work on the photoelectric effect.
The formula is:
Zn + Hcl —> H2 +Zncl2
Hence, the 2 products formed are:
Hydrogen gas and salt
Hope it helps!
<span>1. What causes water's low vapor pressure? (1 point)
dispersion forces
dispersion forces
covalent bonding
hydrogen bonding
ionic attractions
2. Which of the following substances is the most soluble in water? (1 point)
sodium chloride
methane
bromine
carbon
3. Which of the following substances is NOT an electrolyte? (1 point)
KCl
CCl4
LiCl
Na2SO4
4. Which of the following mixture types can be filtered to remove solute? (1 point)
suspensions only
colloids only
suspensions and colloids
suspensions and solutions
5. Which of the following mixtures is NOT a colloid? (1 point)
fog
milk
paint
sugar water
6. Which of the following types of mixtures exhibit the Tyndall effect? (1 point)
suspensions and colloids
suspensions and solutions
colloids and solutions
colloids only
7. An emulsyfying agent is typically characterized by having ____. (1 point)
one polar end
one nonpolar end
one nonpolar end
two polar ends
one polar end and one nonpolar end</span>
