All categories

3 years ago

Which of the following would most likely happen if water did not form hydrogen bonds?

Chemistry

2 answers:

Oksanka [162]3 years ago

8 0

Water would not expand when it freezes.<span> </span>

stellarik [79]3 years ago

3 0

The hydrogen bond is a secondary bond formed between a hydrogen (attached to an highly electronegative element ,: F, O or N) and another atom of an highly electronegative element ,: F, O or N.

In case of water hydrogen bond helps water

a) to dissolve certain substances which can make hydrogen bond

b) it makes it liquid and room temperature unlike H2S which is a gas at room temperature due to absence of hydrogen bond

c) higher volume and low density of ice as compared to liquid water. Due to hydrogen bond ice forms open cage like structure which increases its volume and decreases its density. Thus water expands on freezing

So in absence of hydrogen bond Water would not expand when it freezes.

You might be interested in

A plane takes 230 passengers from New York to Chicago in 3 hours.

devlian [24]

Answer:263mph

Explanation:

3 0

2 years ago

Find the enthalpy of neutralization of HCl and NaOH. 137 cm3 of 2.6 mol dm-3 hydrochloric acid was neutralized by 137 cm3 of 2.6

liraira [26]

Answer : The correct option is, (D) 89.39 KJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.3562 mole of HCl neutralizes by 0.3562 mole of NaOH

Thus, the number of neutralized moles = 0.3562 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $137ml+137ml=274ml$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 274ml=274g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 274 g

$T_{final}$ = final temperature of water = 325.8 K

$T_{initial}$ = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

$q=274g\times 4.18J/g^oC\times (325.8-298)K$

$q=31839.896J=31.84KJ$

Thus, the heat released during the neutralization = -31.84 KJ

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -31.84 KJ

n = number of moles used in neutralization = 0.3562 mole

$\Delta H=\frac{-31.84KJ}{0.3562mole}=-89.39KJ/mole$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 89.39 KJ/mole

3 0

3 years ago

A methanol-water mixture is to be flash distilled at 1 atm. If the feed is 25 mole %methanol, what are the liquid and vapor comp

frozen [14]

Answer:

Explanation:

Given that:

The distillation is carried out at a pressure of 1 atm

The feed harbors 25% mole of methanol (z)

The total moles of feed is usually 100 moles

In the system, we have both methanol and water

Using the total mole balance for the distillation column.

Fz = Lx + Vy

where;

F = amount of feed

z = mole fraction of ethanol (in feed)

L = amount of liquid product out of the column

V = amount of vapor product out of the column

x = mole fraction of methanol out of the liquid

y = mole fraction of methanol out of the vapor.

SO;

(a)

If all the feed is vaporized, then the vapor will likely have the same composition as the feed.

(b)

If no vaporization of the feed takes place, then the bottoms moving out of the column contains the same composition as the feed.

(c)

If 1/3 of the feed is vaporized; then 2/3 of the feed is at the bottom.

The balance equation would be:

$Fz = (\dfrac{2}{3}F) x + (\dfrac{1}{3}F)y \\ \\ z = \dfrac{2}{3}x+\dfrac{1}{3}y$

Replacing z = 0.25; we have:

$0.25 = \dfrac{2}{3}x+\dfrac{1}{3}y$

0.75 = 2x + y

(d)

If 2/3 of the feed is vaporized;

Then:

$Fz = (\dfrac{1}{3}F) x + (\dfrac{2}{3}F)y \\ \\ z = \dfrac{1}{3}x+\dfrac{2}{3}y$

replacing z = 0.25

$0.25 = \dfrac{1}{3}x+\dfrac{2}{3}y$

0.75 = x + 2y

6 0

2 years ago

A cork has a mass of 3 grams and a volume of 16 cms calculate the density

REY [17]

hey mate here is ur answer

solution

mass{m}=3 gram

=3/1000

volume{v}=16cm

=16/100

density=m/v

=3/1000÷16/100

=3/160

=0.01875kg/m3

6 0

3 years ago

Which one has more mass a bag of cotton balls or a bag of nails and explain

Mama L [17]

You would think that the bag of nails would have more mass but their masses are identical. <span>If you were to put them both in a vacuum chamber and let them fall from a great height, they would fall the same speed. The vacuum chamber would suck all of the air out of the cotton balls, thus making it heavier and weigh the same as the bag of nails.

Hopefully this is helpful and makes sense.</span>

6 0

2 years ago