Answer:
5.physical change
6.chemical change
7.physical change
8.conservation of mass
9.thermal energy
10.physical change
I honeslty dont know if this is right
explanation:
Answer : The initial quantity of sodium metal used is 17.25 grams.
Solution : Given,
Volume of gas = 8.40 L
Molar mass of Na metal = 23 g/mole
The Net balanced chemical reaction is,
At STP, 22.4 L of volume is occupied by 1 mole of gas
so, 8.40 L of volume is occupied by = = 0.375 moles of gas
Now from the above reaction, we conclude that
1 mole of gas produced by the 2 moles of Na metal
0.375 moles of gas produced = of Na metal
The quantity of Na metal used = Moles of Na metal × Molar mass of Na metal = 0.75 moles × 23 g/mole = 17.25 grams
Therefore, the initial quantity of sodium metal used is 17.25 grams.
MnO2 is the formula for manganese (4) dioxide
<u>Answer:</u> The equilibrium reaction of trimethylamine with water is written below.
<u>Explanation:</u>
According to the Bronsted-Lowry conjugate acid-base theory:
- An acid is defined as a substance which looses or donates protons and thus forming conjugate base.
- A base is defined as a substance which accepts protons and thus forming conjugate acid.
The equilibrium reaction for the reaction of trimethylamine acting as a weak base in water follows:
Hence, the equilibrium reaction of trimethylamine with water is written above.