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2 years ago

I need helppppp!!!!!!!

Chemistry

1 answer:

Gala2k [10]2 years ago

7 0

Answer:

1. Endothermic

2. Exothermic

3. Exothermic

4. Endothermic

Explanation:

Just the laws of thermodynamics. I always like to remember exothermic as heat exiting or releasing by the phrase "exo" for exit.

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When a cold front passes, the air temperature should begin to rise true or false?

sleet_krkn [62]

False the opposite should happen!

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2 years ago

Read 2 more answers

PLEASE HELP!!!

neonofarm [45]

Answer:

$Cl_2+2NaI\rightarrow I_2+2NaCl$

Explanation:

Hello there!

In this case, according to the described chemical reaction, Cl2 replaces iodine in NaI in order to produce I2 and NaCl:

$Cl_2+NaI\rightarrow I_2+NaCl$

It is possible to realize how chlorine replaces iodine in agreement with the single displacement reaction. Moreover, since chlorine and iodine atoms are not correctly balanced, we add a 2 in front of both NaI and NaCl in order to do so:

$Cl_2+2NaI\rightarrow I_2+2NaCl$

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2 years ago

Each period in the periodic table corresponds to an energy sublevel or the principle energy level?

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Each period in the periodic table corresponds to a principal energy level

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2 years ago

A gas mixture with a total pressure of 745 mmHg contains each of the following gases at the indicated partial pressures: CO2, 24

Setler79 [48]

Answer:

For Part A: The partial pressure of Helium is 218 mmHg.

For Part B: The mass of helium gas is 0.504 g.

Explanation:

For Part A:

We are given:

$p_{CO_2}=245mmHg\\p_Ar}=119mmHg\\p_{O_2}=163mmHg\\P=745mmHg$

To calculate the partial pressure of helium, we use the formula:

$P=p_{CO_2}+p_{Ar}+p_{O_2}+p_{He}$

Putting values in above equation, we get:

$745=245+119+163+p_{He}\\p_{He}=218mmHg$

Hence, the partial pressure of Helium is 218 mmHg.

For Part B:

To calculate the mass of helium gas, we use the equation given by ideal gas:

PV = nRT

or,

$PV=\frac{m}{M}RT$

where,

P = Pressure of helium gas = 218 mmHg

V = Volume of the helium gas = 10.2 L

m = Mass of helium gas = ? g

M = Molar mass of helium gas = 4 g/mol

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of helium gas = 283 K

Putting values in above equation, we get:

$218mmHg\times 10.2L=\frac{m}{4g/mol}\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 283K\\\\m=0.504g$

Hence, the mass of helium gas is 0.504 g.

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Usimov [2.4K]

Answer:

Explanation:

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