10 is mixture of elements and compounds
11 is compound
12-15 are mixture of compounds
Covalent bond is a type of chemical bond which is formed as a result of sharing of electron pairs among the elements that are involved. The structure of the covalent bond is affected by the electronegativity of the elements involved. The molecules joined by covalent bond range in size from very small to very large polymers. There are different types of structures for covalent substances, these include: macromolecular substances, molecular substances and giant covalent structures. Strong bonds hold individual molecules together but there are negligible forces of attraction among them.
Answer:
2.13 V
Explanation:
The balanced equation of the reaction his;
2Cr^3+(aq) + 3Ca(s) -----> 2Cr(s) + 3Ca^2+(aq)
Since this is a galvanic cell then E°cell must be positive. It implies that calcium will be the anode and chromium will be the cathode since calcium is ahead of chromium in the electrochemical series.
E°anode= -2.87 V
E°cathode= -0.74 V
E°cell= E°cathode -E°anode
E°cell= -0.74 -(-2.87)
E°cell = 2.13 V
