_______ have cells that are all dried out.

Weather, such as thunderstorms or rain showers, takes place in the _____. A. troposphere B. mesosphere C. stratosphere D. thermo

sasho [114]

Answer is A)<span> troposphere</span>

6 0

4 years ago

Read 2 more answers

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.

UNO [17]

<u>Answer:</u> The enthalpy change of the reaction is -361.6 kJ

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of sodium = 0.025 moles

Molar mass of sodium = 23 g/mol

Putting values in above equation, we get:

$0.025mol=\frac{\text{Mass of sodium}}{23g/mol}\\\\\text{Mass of sodium}=(0.025mol\times 23g/mol)=0.575g$

We are given:

Mass of water = 100.00 g

Mass of sodium = 0.575 g

Mass of solution = 100.00 + 0.575 = 100.575 g

To calculate the amount of heat absorbed, we use the equation:

$q=m\times C\times \Delta T$

where,

q = amount of heat absorbed = ?

m = mass of solution = 100.575 g

C = specific heat capacity of solution = 4.18 J/g°C

$\Delta T$ = change in temperature = $(T_2-T_1)=(35.75-25.00)=10.75^oC$

Putting all the values in above equation, we get:

$q=100.575g\times 4.18J/g^oC\times 10.75^oC=4519.34J=4.52kJ$

When heat is absorbed by the solution, this means that heat is getting released by the reaction.

<u>Sign convention of heat:</u>

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

$2Na(s)+2H_2O(l)\rightarrow NaOH(aq.)+H_2(g)$

When 0.025 moles of sodium is reacted, the heat released by the reaction is 4.52 kJ

So, when 2 moles of sodium will react, the heat released by the reaction will be = $\frac{4.52}{0.025}\times 2=361.6kJ$

Hence, the enthalpy change of the reaction is -361.6 kJ

6 0

4 years ago

Do the following problem using significant figures.<br> 4.5 cm x 2000.0 cm x 4 cm =<br> I<br> cm^3

Anon25 [30]

Given :

Measurements $4.5\ cm\times 2000.0\ cm\times 4\ cm$ .

To Find :

The multiplication using significant figures .

Solution :

We know , the least number of significant figures in any number of the problem determines the number of significant figures in the answer.

So , significant figure( S.F) in 4.5 cm is 2 .

S.F in 2000.0 cm is 5 .

S.F in 4 cm is 1 .

So , minimum S.F is 1 .

Therefore , S.F of their product is 1 .

Now , multiplying them we will get :

$M=4.5\times 2000.0\times 4 \ cm^3\\\\M=36000\ cm^3$

Now , converting 36000 in 1 significant digit .

First we will write it in exponential 2 S.F form.

$3.6\times 10^4 \ cm^3$

Now , to convert 3.6 into 1 S.F we should round off this .

So , round off 3.6 we will get 4 .

Therefore , The multiplication using significant figures is $4\times 10^4\ cm^3$ .

Hence , this is the required solution .

3 0

3 years ago

What is dew point?

Paraphin [41]

Answer: The clouds formed by condensation are an intricate and critical component of Earth's environment. Clouds regulate the flow of radiant energy into and out of Earth's climate system. They influence the Earth's climate by reflecting incoming solar radiation (heat) back to space and outgoing radiation (terrestrial) from the Earth's surface. Often at night, clouds act as a "blanket," keeping a portion of the day's heat next to the surface. Changing cloud patterns modify the Earth's energy balance, and, in turn, temperatures on the Earth's surface.

8 0

4 years ago

A compound has an empirical formula of CH2 and a molar mass of 70.15. What is its molecular formula?

lina2011 [118]

<h3>Answer:</h3>

Cyclopentane (C5H10)

<h3>Explanation:</h3>

The molar mass of CH2 is about 14.3, Since empirical is a ratio just divide the given molar mass by the molar mass of the empirical. 70.15/14.3=5 So now multiple everything by 5 in the empirical equation.

So, a compound that has an empirical formula of CH2 and a molar mass of 70.15 will have molecular formula of" C5H10".

7 0

3 years ago