I'm guessing it's C-Oxygen because in order to burn something, or create fire, oxygen HAS to be present.
Answer:- 
Explanations:- The solution we have is a buffer solution and we know that a buffer solution resists a change in its pH if a strong acid or base is added to it.
Here, the buffer solution we have is of a weak base and it's conjugate acid. So, a strong acid(nitric acid) is added to this buffer then it reacts with the base present in the buffer so that the acid could be neutralized. This is called buffer action.
The net ionic equation is written as:
Note that 
is a strong acid and nitrate ion is the spectator ion so it is not included in the net ionic equation.
Answer:
B
Explanation:
Homogeneous= all particles are dissolved thoroughly
Solute= 1 gram of salt
Solvent= 500 mL water
Answer:
The SI units for measuring the velocity of the car: meters per second
(m/s)
The Sl units for measuring the acceleration of the car: meters per second squared (m/s^2)
The SI units for measuring force: Newton (N)
The SI units for measuring mass: kilograms (kg)
Explanation:
Système international (SI) or International System of Units consist of a list of unit measurement that mostly used by scientist. The scientist from a different country might use different unit that makes them have to convert the result of each other. The usage of the same unit measurement will help the scientist to read that publication easier, make it easier to share and discuss any topic. The unit used is metric since the decimal system also makes the conversion of a unit easier.
Answer:
2.05moles
Explanation:
The balanced chemical equation in this question is as follows;
Sn + 2H2SO4 → SnSO4 + SO2 + 2H2O
Based on the above equation, 2 moles of H2SO4 reacted to produce 1 mole of SnSO4
However, the mass of SnSO4 produced is 219.65 grams. Using mole = mass/molar mass, we can find the number of moles of SnSO4 produced.
Molar mass of SnSO4 where Sn = 118.7, S = 32, O = 16
= 118.7 + 32 + 16(4)
= 150.7 + 64
= 214.7g/mol
mole = 219.65/214.7
mole = 1.023mol
Therefore, if 2 moles of H2SO4 reacted to produce 1 mole of SnSO4
1.023 mol of SnSO4 produced will cause: 1.023 × 2/1
= 2.046moles of H2SO4 to react.
