Naked lights: lit candles, smoking a cigarette, carrying a box of matches are,<span> prohibited, as they could ignite any methane gas in pockets of the mine.</span>
From the equation of te reaction, we know that the mass percent of NaOH in the mixture is 1.4%.
<h3>What is neutralization?</h3>
Neutralization is a reaction that occurs between an acid and a base to yield salt and water only.
In tis case, the reaction of the NaOH and HCl occurs as follows; NaOH + HCl ----> NaCl + H2O
Number of moles of HCl reacted = 15/1000 * 0.5 moldm-³ = 0.0075 moles
Since the reaction is 1:1, 0.0075 moles of NaOH reacted.
Mass of NaOH = 0.0075 moles of NaOH * 40 g/mol = 0.3 g
Percent of NaOH = 0.3 g/21.10g * 100/1 = 1.4%
Learn more about percent concentration: brainly.com/question/202460
Answer:
O2
Explanation:
At standard temperature and pressure, oxygen is found as a gas consisting of two oxygen atoms, chemical formula O2.
