What element is a non-metal.<br> A. Mg<br> B. Rb<br> C. Li<br> D. Br<br> E. Si

4. How many moles of KBr are found in 3 Liters of 0.4 M solution?

Allisa [31]

There are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.

<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>

The number of moles of a substance can be calculated by multiplying the molarity by the volume.

No. of moles = Molarity × volume

According to this question, 3L of a KBr solution are contained in a 0.4M.

no. of moles = 3L × 0.4M = 1.2moles

Therefore, there are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.

Learn more about no. of moles at: brainly.com/question/14919968

4 0

3 years ago

A system is composed of 7.14 grams of Ne gas at 298 K and 1 atm. When 2025 joules of heat are added to the system at constant pr

dlinn [17]

Answer:

(a) 1 atm, 8.72 L and 298 K respectively.

(b) 1 atm, 16.72 L and 573.35 K respectively.

(c) $\Delta U=1215J$

Explanation:

Hello,

(a) In this case, considering that neon could be considered as an ideal gas, we can compute its volume as follows:

$PV=nRT\\\\V=\frac{nRT}{P}=\frac{7.14g*\frac{1mol}{20g}0.082\frac{atm*L}{mol*K}*298K}{1atm}\\ \\V=8.72L$

Thus, initial conditions of pressure volume and temperature are 1 atm, 8.72 L and 298 K respectively.

(b) Since the process was carried out at constant pressure, the work is defined as:

$W=P(V_2-V_1)$

Thus, the final volume is:

$V_2=\frac{W}{P} +V_1=\frac{810Pa*m^3}{1atm*\frac{101325Pa}{1atm} } *\frac{1000L}{1m^3}+8.72L\\ \\V_2=16.72L$

And the final temperature is computed by considering the pressure-constant specific heat of neon (1.03 J/g*K) and the added heat:

$Q=mCp(T_2-T_1)\\\\T_2=\frac{Q}{mCp}+T_1 =\frac{2025J}{7.14g*1.03J/(g*K)}+298K\\ \\T_2=573.35K$

Therefore, final volume is 16.72 L, final pressure is also 1 atm and final temperature is 573.35 K for this expansion process.

(c) Finally, the change in the internal energy is computed via the first law of thermodynamics:

$Q-W=\Delta U\\\\\Delta U=2025J-810J\\\\\Delta U=1215J$

Best regards.

8 0

3 years ago

Give the common name for the structure. ethyl isopropyl ketone tert-butyl ethyl ketone sec-butyl ethyl ketone ethyl isobutyl ket

salantis [7]

The structure for this question is attached. I think the correct answer would be the fourth option. The common name of the structure would be ethyl isobutyl ketone. Other name would be 2-methyl-3-pentanone. It has a chemical formula of C7H14O or (CH3)2CHCH2C(O)CH2CH3. It is classified as an aliphatic ketone and is used as a solvent and a reagent in laboratory experiments. It is a VOC or volatile organic compound. This compound can also be found at times in normal human biofluids and in feces for about 25% of the population. At normal conditions, it exists as a solid compound.