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3 years ago

Predict which of the following pair will have the higher melting point and indicate why: KBr, Br2.

Chemistry

1 answer:

allsm [11]3 years ago

8 0

Answer:

KBr: strong ion-ion forces

Explanation:

Ionic compounds are non-molecular species. During melting they require a lot of energy input so that the strong ionic bonds that constitute the electrostatic lattice be disrupted. It thus requires very high temperatures. This is indicative of a very strong ion-ion electrostatic interaction which is typical of ionic bonds and results in high melting points of ionic solids.

Hence, the process of melting an ionic solid needs the addition of a large amount of energy in order to break all of the ionic bonds in the crystal.

On the other hand, Br2 is a covalent molecular specie. Most covalent compound have low melting points since their molecules are mostly held together only by weak van der waals forces.

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The combination of potassium-sparing diuretics and salt substitutes can result in dangerously high blood levels of:

alisha [4.7K]

Answer:

b. potassium.

Explanation:

Potassium-sparing diuretics and salt substitutes are diuretics that eliminate salt and water but save potassium. They act by inhibiting the conducting sodium channels in the collecting tubule, such as amiloride and triamterene, or by blocking aldosterone, such as spironolactone.

Concomitant use of potassium-sparing diuretics together with salt substitutes may result in dangerously high blood levels of serum potassium. For this reason, it is important to consult a physician before taking these substances at the same time to avoid potential problems with potassium accumulation.

4 0

3 years ago

Calculate the density of a solid in g/cm3 if it weighs 38.3 kg and has a volume of 0.00463 m3.

RideAnS [48]

Answer: D=8.27 g/cm³

Explanation:

Density is mass/volume. Mass is in grams and volume is in liters. In this case, the problem wants our volume to be in cm³. All we need to do is to make some conversions to convert kg/m³ to g/cm³.

$D=\frac{38.3kg}{0.00463m^3} *\frac{(1m)^3}{(100cm)^3} *\frac{1000g}{1kg}$

With this equation, the m³ and kg cancel out, and we are left with g/cm³.

D=8.27 g/cm³

3 0

3 years ago

Which is the IUPAC name for NO?

Vanyuwa [196]

Answer:

Nitrogen (ii) oxide

Explanation:

To know the IUPAC name for NO, we shall determine the oxidation number of N in NO.

NOTE: The oxidation number of oxygen (O) is always – 2.

Thus the oxidation number of N in NO can be obtained as follow:

N + O = 0 (ground state)

N + (– 2) = 0

N – 2 = 0

Collect like terms

N = 0 + 2

N = +2

Thus, the oxidation number of Nitrogen (N) in NO is +2.

Therefore, the IUPAC name for NO is Nitrogen (ii) oxide

3 0

3 years ago

Read 2 more answers

If 15.0 mL of phosphoric acid completely neutralizes 38.5 mL of 0.150 mol/L calcium hydroxide, what is the concentration of the

Sedbober [7]

Answer:

Let me give it a try.

H3PO4 + Ca(OH)2 = Ca3(PO4)2 + H2O

Balancing this reaction

2H3PO4 + 3Ca(OH)2 == Ca3(PO4)2 + 6H2O.

Moles= Molarity x Volume

Volume = 38.5ml = 0.0385L

Moles of Ca hydroxide = 0.150m/L x 0.0385L

(Notice the units canceling out...leaving moles).

=0.005775moles of Ca(OH)2.

From balanced reaction...

3moles of Ca(OH)2 completely reacts with 2moles of H3PO4

0.005775moles of Ca(OH)2 would completely react with....

= 0.005775 x 2/(3)

=0.00385moles of H3PO4.

Now we're looking for its Concentration in Mol/L

Molarity=Moles of solute/Volume of solution(in L)

Volume of solution assuming no other additions to the reaction = 15ml + 38.5ml =53.5ml =0.0535L

Molarity = 0.00385/0.0535

=0.072Mol/L.

If this is wrong

then Simply Try The formula for Mixing of solutions

C1V1 = C2V2

0.15 x 38.5 = C2 x (15+38.5)

C2 = 0.11M/L.

7 0

3 years ago

SpongeBob & Friends and the Scientific Method

yarga [219]

Answer:

1. Which people are in the control group? The people who received the mint without the secret ingredient

(Group B) would be the control group.

2. What is the independent variable? Secret ingredient in the breath mint

3. What is the dependent variable? Amount of breath odor (or bad breath)

4. What should Mr. Krabs’ conclusion be? The breath mint with the secret ingredient appears to reduce the

amount of breath odor more than half the time, but it is not 100% effective.

5. Why do you think 10 people in group B reported fresher breath? This may be due to the placebo effect.

6 0

3 years ago