Answer:
8.9 g / cm^3
Explanation:
Density = mass / volume
We are given volume which is 10.0cm^3 (cm^3 is just fancy way of saying ml), and mass of 89 gram. Just plug them in respective spots.
Density = 89 / 10.0 = 8.9 g / cm^3
Answer:
It makes the pasta to get hot faster and boil quicker.
Explanation:
Adding salt to water actually raises the boiling point of the water, due to a phenomenon called boiling point elevation. Essentially, adding any non-volatile solute such as salt to a liquid causes a decrease in the liquid’s vapour pressure. A liquid boils when the vapour pressure above it equals atmospheric pressure, so a lower vapour pressure means you need a higher temperature to boil the water. The reason salt makes water boil faster has to do with specific heat capacities, or the energy it takes to raise the temperature of a substance. Salt ions dissolved in water bind to water molecules, holding them stable and making it harder for them to move around. As a result, the non-salt bound water molecules receive more of the energy provided by the stove, and therefore they get hot faster and boil quicker.
Answer:
Option D. KBr < KCl < NaCl
Explanation:
We'll begin by calculating the number of mole of each sample.
This can be obtained as follow:
For NaCl:
Mass = 1 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mole of NaCl =?
Mole = mass /Molar mass
Mole of NaCl = 1/58.5
Mole of NaCl = 0.0171 mole
For Kbr:
Mass = 1 g
Molar mass of KBr = 39 + 80 = 119 g/mol
Mole of KBr =?
Mole = mass /Molar mass
Mole of KBr = 1/119
Mole of KBr = 0.0084 mole
For KCl:
Mass = 1 g
Molar mass of KCl = 39 + 35.5 = 74.5 g/mol
Mole of KCl =?
Mole = mass /Molar mass
Mole of KCl = 1/74.5
Mole of KCl = 0.0134 mole
Summary
Sample >>>>>>>> Number of mole
NaCl >>>>>>>>>> 0.0171
KBr >>>>>>>>>>> 0.0084
KCl >>>>>>>>>>> 0.0134
Arranging the number of mole of the sampl in increasing order, we have:
KBr < KCl < NaCl
Answer:
Pressure for H₂ = 11.9 atm
Option 5.
Explanation:
We determine the complete reaction:
2Al(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)
As we do not know anything about the HCl, we assume that the limiting reactant is the Al and the acid is the excess reagent.
Ratio is 2:3.
2 moles of Al, can produce 3 moles of hydrogen
Therefore 4.5 moles of Al must produce (4.5 . 3) / 2 = 6.75 moles
Now we can apply the Ideal Gases law to find the H₂'s pressure
P . V = n . R . T → P = (n . R .T) / V
We replace data: (6.75 mol . 0.082L.atm/mol.K . 300K) / 14L
Pressure for H₂ = 11.9 atm
