Answer:
This experiment is uncontrolled because two different masses of substance A are used.
Explanation:
A controlled experiment is a structured experiment aimed at testing a particular observation or observations. The setup of a controlled experiment helps to determine the reason why a particular observation occurs and what must have led to it.
In the experiment highlighted above, different masses of a substance were used, they were heated to different temperatures. The set up does not show any correlation between the masses of substances heated and the temperatures. It is even difficult to try to predict the hypothesis for this kind of experimental set up. All the variables in play can best be assumed to be independent of one another.
Answer:
eye wash: if you get chemicals in your eyes it helps to clean it
chemical/safety shower; If chemical gets on your skin everywhere you need to take a shower immediately so it helps you get rid of the chemicals on your skin
fire extinguisher: if something cashes on fire you need that to extenguish it
Explanation:
Answer: NaCl>HCl&H2O> N2
Explanation:
NaCl, as an ionic substance has a very high boiling point as expected. However, the boiling points of HCl and H2O depend on the relative concentration of the HCl and water, at 20% HCl, it boils at almost the same temperature as water due to extensive intermolecular hydrogen bonding. N2 comprises only of Vanderwaals forces hence it has the least boiling point.
If you have an aqueous solution that contains 1.5 moles of HCl, the number of moles of ions in the solution is 3.0 moles.
<h2>Further Explanation
</h2><h3>Strong acids </h3>
- Strong acids are types of acids that undergo complete dissociation to form ions when dissolved in water.
- Examples of such acids are, HCl, H2SO4 and HNO3
- Dissociation of HCl
HCl + H₂O ⇔ H₃O⁺ + OH⁻
<h3>Weak acids </h3>
- Weak acids are types of acids that undergo incomplete dissociation to form ions when dissolved in water.
- Examples of such acids are acetic acids and formic acids.
- Dissociation of acetic acid
H₃COOH ⇔ CH₃COO⁻ + H⁺; CH₃COO⁻ is a conjugate base of acetic acid.
<h3>In this case;</h3>
- HCl which is a strong acid that ionizes completely according to the equation;
HCl + H₂O ⇔ H₃O⁺ + OH⁻
- From the equation, 1 mole of HCl produces 1 mole of H₃O⁺ ions and 1 mole of OH⁻ ions.
Therefore;
1.5 moles of HCl will produce;
= 1.5 moles of H₃O⁺ ions and 1.5 moles of OH⁻ ions.
This gives a total number ions of;
= 1.5 + 1.5
= 3 moles of ions
Keywords: Strong acid, weak acid, ions, ionization
<h3>Learn more about: </h3>
Level: High school
Subject: Chemistry
Topic: Salts, Acids and Bases
The mass sample of nicotine combusted = 2.625 mg (given)
Mass of 
produced = 7.1210 mg (given)
Mass of 
produced = 2.042 mg (given)
Molar mass of = 44 g/mol
Molar mass of = 18 g/mol
Percentage of Carbon = 
%
Percentage of hydrogen = 
%
Now, for percentage of nitrogen = 
%
Calculating the moles of each element:
- For
- For
- For
Dividing with the smallest mole value to calculate the molar ratio of each element:
Hence, the empirical formula for nicotine is 
.
