The “reaction of sodium hydroxide and hydrochloric acid”
Romeo and Juliet just may end happily after all
You won’t find the country of Chemistry on a world map, but it exists nonetheless. Life there is every bit as rich and varied as in any other realm – and sometimes even more so. Even “Romeo and Juliet” has a happy ending there. But let’s not get ahead of ourselves; we’ve got a lot to do. We’ll meet the chemical Montagues and Capulets, select the finest candidate for the “reaction of sodium hydroxide and hydrochloric acid,” set off into space, visit the world’s finest restaurant, and ever so much more.
Let’s first visit the chemical laboratory.
In any laboratory where safety rules are observed and respected, alkalis and their ilk are kept strictly separate from acids and their ilk. These are the Montagues and Capulets of Chemistry: both families are aggressive and implacably hostile. If they meet without a Chemist’s supervision, it bodes only disaster! Nor do they spare the Chemists – they yearn to burn or poison them. So if the Chemists intend to have dealings with them, they must protect themselves as best they can: they have no recourse but to work with them in a fume hood, and wear a lab coat, apron, gloves, special boots, and glasses or a protective shield.
But it just so happened that the handsome Sodium Hydroxide, from the Alkali family, fell in love with the enchanting Hydrochloric Acid – from the Acid family!
Chemical formula NaOH. One of the most widespread alkalis, also known as caustic soda.
A solid white or slightly yellowish powder; hygroscopic; corrodes many materials and organic substances including paper, skin, and even some metal;, dissolves in water, ethyl and methyl alcohols.
A strong base that reacts with:
- amphoteric oxides;
- amphoteric hydroxides;
- salts in solution;
- esters, amides, and alkyl halides
- polyatomic alcohols.
Field of application
- chemical industry;
- processing industry;
- pulp and paper industry;
- civil defense as a neutralizing substance;
- food industry – to remove the skins from fruits and vegetables, in the manufacture of chocolate and cacao, and to soften olives and give them a dark color;
- cosmetics – to remove keratinized skin;
- the household.
Now, let’s acquaint ourselves with hydrochloric acid.
Chemical formula HCl. A strong mineral monobasic hydracid.
Colorless, transparent, a caustic liquid that fumes in the air. Maximum concentration at 20 °C is 38%, with a solution density of 1.19g/cm³. Highly-concentrated acid causes severe burns if it encounters skin, mucous membranes or eyes, but is present in the human stomach at a concentration of around 0.5%.
A strong acid that reacts with:
- metal hydroxides;
- metal oxides;
- metal salts;
- strong oxidizers;
- ammonium. An interaction with silver nitrate serves as a qualitative reaction to test for hydrochloric acid and its salts.
Field of use:
- hydrometallurgy and electrotyping;
- chemical industry;
- food industry as the food additive E507;
- medicine – to treat low acidity in the stomach.
And so a Chemist decided to reconcile the two hostile families and marry the lovers, to do everything to make sure that the “reaction of sodium hydroxide with hydrochloric acid” proceeded as planned. A phenolphthalein indicator served as the bridesmaid for the “acid” bride. As soon as the reaction with the hydroxide took place, the colorless indicator crimsoned with delight. Despite the aggression of the sodium hydroxide and hydrochloric acid, the reaction was a wonderful one. And its equation reads as follows:
HCl + NaOH = NaCl + H₂O + Q
Hydrochloric acid and sodium hydroxide interact, resulting in salt and a release of heat.
As we can see, the result of the interaction of two highly aggressive compounds is table salt and water – compounds that are ultimately harmless, even beneficial, to human beings. And thus the two warring families ceased their aggressions and made peace.
To assess the products of the reaction properly, let’s get in a rocket and venture into space. We’ll look at our planet from a distance. It’s called the blue planet for good reason, as 71% of its surface is comprised of seas and oceans. Although, to be fair, we should note that only 1% of this water is suitable for consumption. And water is one of the products of our reaction.
And now let’s visit the best of restaurants – you decide which! Let’s proceed into the kitchen and ask the chef what two ingredients they couldn’t do without. And believe us, they won’t say caviar, truffles, or parmesan, they’ll say salt and water, as without these ingredients you can’t prepare a single dish. And in combination, our reaction products can be found at home in soup, brine, or salt water. And now let’s dive in even deeper, examining the reaction of sodium hydroxide and hydrochloric acid in the classification of chemical reactions.
Determining the type of chemical reaction of hydrochloric acid with sodium hydroxide
1. By the number and state of the reactants and products, it is an exchange reaction. In other words, the number of substances entering into the reaction is equal to the number of substances received as a result of the reaction. An simple exchange of ions has taken place. To clarify, let’s write our reaction equation in ionic form:
H⁺ + Cl⁻ + Na⁺ + OH⁻ = Na⁺+Cl⁻ + H₂O
In accordance with our story, the bride and groom have exchanged their personal property: what’s mine is yours. Here you can find out more about this dowry.
2. By the type of interacting substances, it is a neutralization reaction.
H⁺ + OH⁻ = H₂O
3. By the physical state of substances, it is homogenous. The substances entering into the reaction are in an identical physical state – an identical liquid state.
4. By the direction of the course of the reaction, it is irreversible. The reaction continues till the very end, until the reacting substances are completely consumed.
5. By thermal effect, it is exothermic. In other words, the wedding ceremony took place in a warm, friendly, and loving atmosphere. The reaction is accompanied by a thermal effect, and the amount of heat released is 57.3 kJ/mol.
6. The reaction is not an oxidation-reduction reaction: the oxidation states of the atoms did not change over the course of the reaction.
H⁺Cl⁻ + Na⁺O²⁻H⁺ = Na⁺Cl⁻ + H⁺ O²⁻
And thus, our love story has a happy ending: lovers from two hostile families have joined together in unity.
The aggressive sodium hydroxide and hydrochloric acid interacted, and the result yielded useful products.
Isn’t chemistry a wonderful science? Via a reaction between an acid and an alkali, we have turned the saddest of tragedies into a joyful romance!