Answer : The mass of sodium bromide added should be, 18.3 grams.
Explanation :
Molality : It is defined as the number of moles of solute present in kilograms of solvent.
Formula used :
Solute is, NaBr and solvent is, water.
Given:
Molality of NaBr = 0.565 mol/kg
Molar mass of NaBr = 103 g/mole
Mass of water = 315 g
Now put all the given values in the above formula, we get:
Thus, the mass of sodium bromide added should be, 18.3 grams.
Answer:
4) 1.5 mol
Explanation:
Well, the equation is already balanced and the mole to mole ratio of reactants and products are all 1. So if the limiting reactant is HCl and you have 1.5 mol, you do the mole to mole ratio with NaCl and since it is 1 to 1, there'd be 1.5 mol of NaCl.
Answer:
01) Cu tting hair is a physical change. reason-1
02) Cooking can be either one, but I would choose chemical reason-3
03) Ice cream melting is a physical change reason-2
Explanation:
Metals usually become cations since electrons are negatively charged and when they are lost there are more protons than electrons making a positive net charge in the atom. (cations are positively charged ions while anions are negatively charged ions)
I hope this helps. Let me know if anything is unclear.
Answer: option <span>A) increases from bottom to top within the group.
Explanation:
</span>It is a known trend that the metallic character of the elements increase from let to right and from top to bottom.
The greater the metallic character the greater the reactivity of the metal.
So, the elements of the columns 1 and 2 are the most reactive metals and among them the elements at the bottom are yet more reactive.
<span>The higher reactivity of the metals that are lower in the periodic table is attributed to the greater total number of electrons.
The greater the total number of electrons the more reactive the metals
as their outermost electrons (the valence electrons which are those that react) are located further from the nucleus and therefore they are held less
strongly, which makes them react more easily.</span>
