Answer: Significant figures are important to show the precision of your answer. This is important in science and engineering because no measuring device can make a measurement with 100% precision. Using Significant figures allows the scientist to know how precise the answer is, or how much uncertainty there is.
Explanation:
Answer:
2NaCN + CaCO3 --> Na2CO3 + Ca(CN)2
Explanation:
Knowing the names gets us: NaCN + CaCO3 --> Na2CO3 + Ca(CN)2
Balance: there are two sodiums and cyanides on the product side so add a 2 to the reactant side.
Answer : The balanced redox reaction will be,

Explanation :
The given chemical equation is,

In the half reaction method, the number of atoms in each half reaction and number of electrons must be balanced.
The half reactions in the acidic medium are :
Reduction :
......(1)
Oxidation :
.......(2)
Now multiply the equation (2) by 4 and then added both equation, we get the balanced redox reaction.
Thus, the balanced redox reaction will be,
