PLEASE HELP! an element with 8 protons and 10 neutrons

How many joules of heat are required to heat 25.0 g of isopropyl alcohol from the prevailing room temperature, 21.2 oC, to its b

valentinak56 [21]

Answer:

3984.12 J joules of heat are required to heat 25.0 g of isopropyl alcohol to its boiling point.

Explanation:

$Q=m\times c\Delta T=m\times c\times (T_2-T_1)$

Where:

Q = heat absorbed or heat lost

c = specific heat of substance

m = Mass of the substance

ΔT = change in temperature of the substance

$T_1$ = Initial temperature of the substance

$T_2$ = Final temperature of the substance

We have mass of isopropyl alcohol = m = 25.0 g

Specific heat of isopropyl alcohol = c = 2.604 J/g°C

Initial temperature of the isopropyl alcohol = $T_1=21.2^oC$

Final temperature of the isopropyl alcohol = $T_2=82.4 ^oC$

Heat absorbed by the isopropyl alcohol to boil:

$Q=25.0 g\times 2.604 J/g^oC\times (82.4^oC-21.2^oC)=3984.12 J$

3984.12 J joules of heat are required to heat 25.0 g of isopropyl alcohol to its boiling point.

7 0

3 years ago

What are elements and how many elements discovered

Yuliya22 [10]

Explanation:

At present, 118 elements are known to us. All these have different properties. Out of these 118, only 94 are naturally occurring. As different elements were being discovered, scientists gathered more and more information about the properties of these elements.

7 0

3 years ago

Read 2 more answers

A balloon filled with helium gas occupies 2.50 L at 25°C and 1.00 atm. When released, it rises to an altitude where the temperat

stira [4]

Answer:

8,19 L

Explanation:

The combined gas law is a equation that can be used when the initial and final conditions -pressure,volume,amount of moles,temperature-, of a gas change during a process. It can be written:

$\frac{P1V1}{n1T1}=\frac{P2V2}{n2T2}$

If the amount of the gas remains constant, then n1=n2 and we have:

$\frac{P1V1}{T1}=\frac{P2V2}{T2}$

For the problem we have:

Note: When working with gases is important to use absolute temperature values (°K, °K=°C+273,15):

P1=1 atm, V1=2,5L, T1=25+273,15=298,15°K

P2=0,3 atm, V2=?, T2=20+273,15=293,15°K

$V2=\frac{P1V1T2}{T1P2}=\frac{1atm*2,5L*293,15K}{298,15K*0,3atm}=8,19L$

The new volume of the balloon is 8,19 L.

5 0

3 years ago

A student writes the following explanation of how certain molecules are formed.A process is used to chemically link smaller unit

tensa zangetsu [6.8K]

Answer:

polymerization

Explanation:

Student is explaining the process of formation of a polymer and the process is called polymerization.

Polymer is made up of joining repeating units. The repeating units are called monomers.

Properties of the polymer is determined by the structure of monomer molecule.

For example, consider a well-known polymer Teflon.is made by the polymerization of tetrafluoroethane.

Thus, the student is explaining polymerization.

8 0

4 years ago

Nuclear physicists have discovered over 100 different particles that compose the nucleus of an atom. From a chemistry perspectiv

Julli [10]

Answer:

Protons and neutrons which packed tightly into central core of the atom.

Explanation:

Atoms are composed of three subatomic particle; electron, proton and neutron. Electrons are negatively charged, protons are positively charged whereas neutrons are neutral, hence does not have any charge.

Out of three, protons and neutrons are present in the nucleus of the atom.

Nucleus is the central part of the atom possessing most of the mass of the atom. In the nucleus, protons and neutrons are tightly packed with the help of nuclear force.

Electrons are present around the nucleus also called electron cloud.

Therefore, nucleus are composed of protons and neutrons which packed tightly into central core of the atom

4 0

3 years ago