Answer:
Explanation:
mole of HCl remaining after reaction with CaCO₃
= .3 M of NaOH of 32.47 mL
= .3 x .03247 moles
= .009741 moles
Initial HCl taken = .3 x .005 moles = .0015 moles
Moles of HCl reacted with CaCO₃
= .009741 - .0015 = .008241 moles
CaCO₃ + 2HCl = CaCl₂ + CO₂ + H₂O .
1 mole 2 moles
2 moles of HCl reacts with 1 mole of CaCO₃
.008241 moles of HCl reacts with .5 x .008241 moles of CaCO₃
CaCO₃ reacted with HCl = .5 x .008241 = .00412 moles
the mass (in grams) of calcium carbonate in the tablet
= .00412 x 100 = .412 grams . ( molar mass of calcium carbonate = 100 )
Answer:
four covalent bonds
Explanation:
A carbon atom would form 4 covalent bonds.
For a covalent bond to be formed, an atom would share its valence electrons with another. In this process, each atom would require unpaired electrons for this bond to be formed. The number of available unpaired electrons would represent the number of electrons needed to complete the outer energy level of the atom.
In a carbon atom, we have no lone pair of electrons and 4 unpaired electrons. When these 4 electrons are shared with those of other atoms, they produce a complete octet which perfectly mimics the noble gases.