You can automatically rule out CH₄ since it has no lone pairs at all around the central atom. Water has 2. Ammonia is the only Lewis structure that contains one lone pair.
For the first question, salt is soluble while sand is insoluble or not dissolvable in water. The salt should have vanished or melted, but the sand stayed noticeable or visible, making a dark brown solution probably with some sand particles caught on the walls of the container when the boiling water was put in to the mixture of salt and sand. The solubility of a chemical can be disturbed by temperature, and in the case of salt in water, the hot temperature of the boiling water enhanced the salt's capability to melt in it.
For the second question, the melted or dissolved salt should have easily made its way through the filter paper and into the second container, while the undissolved and muddy sand particles is caught on the filter paper. The size of the pores of the filter paper didn’t change. On the contrary, the size of the salt became smaller because it has been dissolved which is also the reason why it was able to go through the filter paper, while the size of the sand may have doubled or even tripled which made it harder to pass through.
The number of moles in each sample will be 0.391 moles, 30.7 moles, 0.456 moles, and 1350 moles
<h3>What is the number of moles?</h3>
The number of moles of a substance is the ratio of the mass of the substance to the molar mass.
In other words; mole = mass/molar mass.
Thus:
- moles of 18.0 g
= 18.0/46
= 0.391 moles
- moles of 1.35 kg
= 1350/44
= 30.7 moles
- moles of 46.1 g
= 46.1/101.1
= 0.456 moles
- moles of 191.8 kg
= 191800/142
= 1350 moles
More on the number of moles of substances can be found here: brainly.com/question/1445383
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Answer:
An acid is a substance that donates hydrogen ions. Because of this, when an acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted. Now there are more hydrogen ions than hydroxide ions in the solution. This kind of solution is acidic.
Explanation:
