All categories

3 years ago

Can someone please help me with these three questions, it will soon be due.

Chemistry

1 answer:

Mice21 [21]3 years ago

8 0

YOU also better mark me BRAINLIEST if someone else answers!!!

volume = 100 mL

density = 1.02 g / mL

mass = density x volume

= 1.02 x 100
= 102 g

Cp = 4.03 J / oc g
dT = 28.7 - 23.5 = 5.2 oC
Q = m Cp dT
Q = 102 x 4.03 x 5.2
Q = 2138 J
Q = 2.14 kJ

heat absorbed = 2.14 kJ

We can calculate the moles of HC1 present in 50 ml 1m solution by using the formula, moles = volume of solution in L*molarity
moles = 50/1000 = .05 , L*1 M = .05 Moles of HCL.
The same can be applied for calculation of moles fo Na OH of 50 ml, 1 M solution. (50 ml NaOH = .o5 L NaOH)
Then use the formula = volume of solution / 1000*moles.wt,
=1.825 gram.
moles=mass in grams /moles.wt= .05 moles of HCI
calculate moles of water from this reaction.
HC1+NaOH----->NACl+h20 (Balanced Equation)
.5+.5----> .5+.5
.05 moles of water
Delta H=q/n.
n=.05 to calculate the Delat H.

3) I don't understand it, sorry

You might be interested in

Which cells produce photosynthesis

AnnZ [28]

Hey there,

Answer:

Photosynthetic cell

Hope this helps :D

<em>~Top♥</em>

6 0

3 years ago

When Brian first sorted out his thoughts, he figured this was the first day after the crash and what did he think would happen n

Leya [2.2K]

It should be noted that when Brian first sorted out his thoughts, the first thing that he thought would happen next is that he would probably be rescued that day.

It should be noted that in Chapter 5 of Hatchet, Brian wakes up in the forest and then, he realized that he was desperately thirsty.

When Brian first sorted out his thoughts, he figured this was the first day after the crash and that he would probably be rescued that day. He believed that he was going to wither up and die if he doesn't get anything that he'll drink.

Learn more about excerpts on:

brainly.com/question/21400963

7 0

2 years ago

Air at 293 K and 750 mm Hg pressure has a relative humidity of 80%. What is its percent humidity? The vapour pressure of water a

Mekhanik [1.2K]

Answer : The correct option is, (c) 79.62

Explanation :

The formula used for percent humidity is:

$\text{Percent humidity}=\text{Relative humidity}\times \frac{p-p^o_v}{p-p_v}\times 100$ ..........(1)

The formula used for relative humidity is:

$\text{Relative humidity}=\frac{p_v}{p^o_v}$ ...........(2)

where,

$p_v$ = partial pressure of water vapor

$p^o_v$ = vapor pressure of water

p = total pressure

First we have to calculate the partial pressure of water vapor by using equation 2.

Given:

$p=750mmHg$

$p^o_v=17.5mmHg$

Relative humidity = 80 % = 0.80

Now put all the given values in equation 2, we get:

$0.80=\frac{p_v}{17.5mmHg}$

$p_v=14mmHg$

Now we have to calculate the percent humidity by using equation 1.

$\text{Percent humidity}=0.80\times \frac{750-17.5}{750-14}\times 100$

$\text{Percent humidity}=79.62\%$

Therefore, the percent humidity is 79.62 %

4 0

4 years ago

A sample of nitrogen occupies 10.0 liters at 25°C and 98.7 kPa. What would be the volume at 20°C and 102.7 kPa?

krek1111 [17]

To solve the problem, we assume the sample to be ideal. Then, we use the ideal gas equation which is expressed as PV = nRT. From the first condition of the nitrogen gas sample, we calculate the number of moles.

n = PV / RT
n = (98.7x 10^3 Pa x 0.01 m^3) / (8.314 Pa m^3/ mol K) x 298.15 K
n = 0.40 mol N2

At the second condition, the number of moles stays the same however pressure and temperature was changed. So, the new volume is calculated as follows:

V = nRT / P
V = 0.40 x 8.314 x 293.15 / 102.7 x 10^3
V = 9.49 x 10^-3 m^3 or 9.49 L

7 0

3 years ago

What happens when the sun beats up the earth

frozen [14]

Then we all die because the sun would blow up the earth.

7 0

3 years ago