Reaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour. The reaction is slower than that of potassium (immediately below sodium in the periodic table), but faster than that of lithium (immediately above sodium in the periodic table).
2Na(s) + 2H2O → 2NaOH(aq) + H2(g)
Answer:
40.3 for the unit that represents the minimum amount of magnesium oxide I beilieve.
Explanation:
Magnesium atoms are heavier than oxygen atoms, so we expect more than 50% of magnesium in the weight composition. Taking just one atom of Mg and one atom of O you will get a mass of 16.0 + 24.3 = 40.3.
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Answer:
17.5 g
Explanation:
Given data
- Mass of solution to be prepared: 50.0 grams
- Concentration of the salt solution: 35.0%
The concentration by mass of NaCl in the solution is 35.0%, that is, there are 35.0 grams of sodium chloride per 100 grams of solution. We will use this ratio to find the mass of sodium chloride required to prepare 50.0 grams of a 35.0% salt solution.
Answer:
Option B
Explanation:
Salt is a non-volatile solute and hence adding salt will increase the boiling point of water and hence reduce the vapor pressure. While on the other hand, adding more water will require more time to boil and hence produce vapor and thus the vapor pressure. Shaking will also not help in increasing the vapor pressure. Thus, only increasing the temperature of the water will create more vapors at a faster rate and hence increase the vapor pressure.
Thus, option B is the correct answer
If the element is oxidized, then it's oxidation number would increase.
Let's say we have the following reaction.
2H2O --> O2 + 2H2
To the left, the oxidation number of O is -2, as it is bonded to two H, which is always H+. To the right, we have O2, and all gases have a oxidation number of 0 (zero). We say that O has been oxidized.
