Isotopes are atoms of the same element with different numbers of

How are the graphs of the sine function and the cosine function different?

Zielflug [23.3K]

They are different by a phase shift of pi/2

3 0

2 years ago

Assuming equal concentrations and complete dissociation, rank these aqueous solutions by their freezing points. nh4cl cobr3 k2so

Illusion [34]

Answer: CoBr3 < K2SO4 < NH4 Cl

Justification:

1) The depression of the freezing point of a solution is a colligative property, which means that it depends on the number of particles of solute dissolved.

2) The formula for the depression of freezing point is:

ΔTf = i * Kf * m

Where i is the van't Hoof factor which accounts for the dissociation of the solute.

Kf is the freezing molal constant and only depends on the solvent

m is the molality (molal concentration).

3) Since, you are assuming equal concentrations and complete dissociation of the given solutes, the solute with more ions in the molecular formula will result in the solution with higher depression of the freezing point (lower freezing point).

4) These are the dissociations of the given solutes:

a) NH4 Cl (s) --> NH4(+)(aq) + Cl(-) (aq) => 1 mol --> 2 moles

b) Co Br3 (s) --> Co(3+) (aq) + 3Br(-)(aq) => 1 mol --> 4 moles

c) K2SO4 (s) --> 2K(+) (aq) + SO4 (2-) (aq) => 1 mol --> 3 moles

5) So, the rank of solutions by their freezing points is:

CoBr3 < K2SO4 < NH4 Cl

4 0

3 years ago

Read 2 more answers

HELP ASAP! Chemical reactions involving liquids only will be influenced by ALL of the following EXCEPT: a) temperature of the sy

Rom4ik [11]

<span>Chemical reactions involving only liquids will be influenced by ALL of the following EXCEPT: </span><span><span>c) size of reactant particles d) pressure of the system.

</span>Reason:
1) As per Arrhenius theory, rate of chemical reactions is influence by temperature. Mathematically it is expressed as: k = A exp(-Ea/RT)
</span>where, k = rate constant, A = collision frequency, Ea = activation energy, T = temp. From above relation, it can be seen that, chemical reactions involving only liquids will be influenced temperature.

2) Also, if know that, rates of chemical reactions is mathematically expressed as: $Rate = [A]^{x} B^{y}....$ ,
where A, B, .. are the reactants.
From above relation, it can be seen that, chemical reactions involving only liquids will be influenced concentration i.e. number of particle.

3) However, since all the reactant and catalyst used (if any) is in liquid state, particle size of same will not influence the reaction.

4) Also, since there are no gas-phase reactant, pressure will not affect the reaction.

8 0

2 years ago

1

trasher [3.6K]

Answer:

I believe the answer is B

Explanation:

A nucleus of an atom has protons and neutrons. We know that a proton has a charge of +1 , while a neutron has no charge, or 0 . Therefore, the nucleus of an atom will always have a positive charge.

6 0

2 years ago

Write the fraction of the mass of kcl produced from 1 g of k2c03

Minchanka [31]

Mass of KCl= 1.08 g

<h3>Further explanation</h3>

Given

1 g of K₂CO₃

Required

Mass of KCl

Solution

Reaction

K₂CO₃ +2HCl ⇒ 2KCl +H₂O + CO₂

mol of K₂CO₃(MW=138 g/mol) :

= 1 g : 138 g/mol

= 0.00725

From the equation, mol ratio K₂CO₃ : KCl = 1 : 2, so mol KCl :

= 2/1 x mol K₂CO₃

= 2/1 x 0.00725

= 0.0145

Mass of KCl(MW=74.5 g/mol) :

= mol x MW

= 0.0145 x 74.5

= 1.08 g

6 0

3 years ago