Question
Question: What metal will have properties most similar to chromium?...
What metal will have properties most similar to chromium?
Solution
Chromium is placed in group VI−B . Its properties are similar to the other members of the group. The group VI−B contains chromium, molybdenum, tungsten and seaborgium. The members of this group do not show patterns in its electronic configuration far from other groups as the two lighter members of this group are exceptions from the Aufbau principle.
Complete answer:
Group VI−B is the group consisting of transition metals in which chromium, molybdenum and tungsten are refractory metals. Most of the chemistry deals with the first three members of the group VI−B . The chemistry of seaborgium is not established and therefore the rest of the section only deals with upper neighbours.
Metals which are similar to chromium are molybdenum and tungsten. They are similar to chromium as they lie in the same group and have the same properties.
Chromium is the twenty-first most abundant element by weight in the earth’s crust. Molybdenum and tungsten are quite rare. Like chromium, molybdenum and tungsten are hard and have very high melting points and have low volatility. The melting point of W is the next highest to carbon. The oxides of MoO3 and WO3 are strongly acidic and dissolve in aqueous NaOH forming discrete tetrahedral molybdate MoO42− and tungstate WO42− ions same as oxides of CrO3 form chromate CrO42− .
Note:
Remember the electronic configuration of Cr and Mo are the same but W is different. The electronic configuration of Cr and Mo is (n−1)d5ns1 whereas the electronic configuration of tungsten is (n−1)d5ns2 . Cr dissolves in HCl and H2SO4 , but is passivated by HNO3 or aqua regia. Mo and W are relatively inert and are only slightly attacked by aqueous acids and alkalis.