Balancing Reactions
When you balance a reaction, which number can you never change?
The subscript in the molecule (i.e. "2" in CO2)
Convert 2.6 grams of Si2O3 to mole
0.025 mole
Why was it necessary to heat the hydrate in order to determine the chemical formula of the hydrate?
The mass loss will help you find the grams of water. Since you know the total grams of the hydrate, once you know the grams of water, you can get the grams of the salt. From both the grams of the salt and the water, you can get the moles of the salt and water. Then you can find the simplest whole number ratio.
What should you do if one of the coefficients in the balanced reaction is a number like 2.5?
Multiply the entire reaction by 2.
Convert 0.8 mole of NH3 to grams
1.36 grams
Why is it unlikely during the breakdown of KClO3 that we would form KCl?
We didn't use a catalyst to speed up the breakdown of KClO3. Just heating KClO3 is not enough.
What is the recommended sequence of balancing elements in a combustion reaction?
1.Balance C first
2.Balance H next
3.Balance O last
Convert 8.4 g Si to atoms.
1.8x10^23 atoms
Why is the reformation of the hydrate from the salt exothermic?
It required heat to break down the hydrate. This means that the decomposition of the hydrate is endothermic. The reformation of the hydrate is the opposite process, making the process exothermic.
Balance the reaction:
__Al2O3 + ___Fe -----> ___Fe3O4 + ___Al
4Al2O3 + 9Fe ----> 3Fe3O4 + 8Al
Convert 1.2x10^23 atoms of C to grams
2.4 grams
Given the data below, find the chemical formula of the hydrate:
crucible: 30.5 grams
crucible + Ba(NO3)2 xH2O:31.5 g
crucible + Ba(NO3)2; 31.38 g
Ba(NO3)2 (2H2O)
We already know that mass is conserved in a balanced reaction. Why is energy also conserved in a balanced reaction.
Although bonds break and new bonds form, energy is inputted if necessary or energy is released.
Convert 30 grams of SiO2 to atoms
9x10^23 atoms
Given the data:
Mass KClO3: 0.8 g
Mass O2 released: 0.21 g
Find the x-value in KClOx
x=1