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.
This is late but for anyone else who needs it...It's D. Far left
Answer:
0.289J of heat are added
Explanation:
We can relate the change in heat of a substance with its increasing in temperature using the equation:
q = m*ΔT*S
<em>Where Q is change in heat</em>
<em>m is mass of substance (In this case, 0.0948g of water)</em>
<em>ΔT = 0.728°C</em>
<em>S is specific heat (For water, 4.184J/g°C)</em>
Replacing:
q = 0.0948g*0.728°C*4.184J/g°C
q = 0.289J of heat are added
The average weight of an atom of an element, formerly based on the
weight of one hydrogen atom taken as a unit or on 1/16 (0.0625) the
weight of an oxygen atom, but after 1961 based on 1/12 the weight of the
carbon-12 atom.
Answer:
17.5moles
Explanation:
The number of moles in a substance can be calculated by using the formula;
Number of moles (n) = mass (m) ÷ molar mass (MM)
According to this question, mass of ammonia (NH3) = 297g
Molar Mass of NH3 = 14 + 1(3)
= 17g/mol
n = 297/17
n = 17.47
Number of moles of NH3 = 17.5moles
