Properties of a solution that depend only on the ratio of the number of particles of solute and solvent in the solution are known as colligative properties. For this problem, we use boiling point elevation concept.
ΔT(boiling point) = (Kb)mi
ΔT(boiling point) = (0.51 C-kg / mol )(4.0 mol / 2.05 kg ) (2)
ΔT(boiling point) = 1.99 C
T(boiling point) = 101.99 C
Problem One
You will use both m * c * deltaT and H = m * heat of fusion.
Givens
m = 12.4 grams
c = 0.1291
t1 = 26oC
t2 = 1204
heat of fusion (H_f) = 63.5 J/grams.
Equation
H = m * c * deltaT + m * H_f
Solution
H = 12.4 * 0.1291 * (1063 - 26) + 12.4 * 63.5
H = 1660.1 + 787.4
H = 2447.5 or 2447.47 is the exact answer. I have to leave the rounding to you. I have no idea where to round it although I suspect 2450 would be right for 3 sig digs.
Problem Two
Formula and Givens
t1 = 14.5
t2 = 50.0
E = 5680
c = 4.186
m = ??
E = m c * deltaT
Solution
5680 = m * 4.186 * (50 - 14.5)
5680 = m * 4.186 * (35.5)
5680 = m * 148.603 * m
m = 5680 / 148.603
m = 38.22 grams That isn't very much. Be very sure you are working in joules. You'd leave that many grams in the kettle after drying it thoroughly.
m = 38.2 to 3 sig digs.
Answer: A. an electron
<u>Beta particles are electrons or positrons (electrons with positive electric charge or antielectrons).</u> Beta decay is a type of radioactive decay in which a beta ray is emitted from an atomic nucleus.
<u>Beta decay occurs when, in an unstable nucleus with too many protons or too many neutrons, one of the protons or neutrons transforms into the other.</u> In beta minus decay, a neutron is broken down into a proton, an electron, and an antineutrino (the neutrino antiparticle, meaning it has an opposite charge to the neutrino). In beta decay plus, a prototype breaks down into a neutron, a positron and a neutrino.
Answer:
Molar mass
Explanation:
This is a counting unit which represents the mass in grams of a substance that make up one mole of the substance. This mass is calculated as follows:
Molar mass = Mass/ Number of moles
Units: grams/mol
