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nikklg [1K]
3 years ago
10

Pretend your friend was absent from class today...

Chemistry
2 answers:
NemiM [27]3 years ago
7 0
Incomplete question
Dovator [93]3 years ago
5 0

Answer:

how and why elements what?? why they exist?? im gonna assume that's what you meant, so elements exist because we're all on earth and without elements, we don't have resources to live. the earth is made of elements and if there were none, we wouldn't even have a planet

Explanation:

^

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Standard temperature and pressure (STP), in the context of gases, refers to a) 298.15 K and 1 atm b) 273.15 K and 1 atm c) 298.1
lina2011 [118]

Answer : The correct option is, (B) 273.15 K and 1 atm

Explanation :

STP : STP stands for standard temperature and pressure.

STP conditions :

The temperature is, 0^oC or 273.15K or 32^oF

The pressure is, 1atm or 101.325kPa

The volume is 22.4 L for 1 mole of a substance.

Hence, the correct option is, (B) 273.15 K and 1 atm

7 0
3 years ago
How does physical properties differ from chemical properties?
juin [17]
It's A. 
Chemical properties cannot be determined by viewing or touching substance, and physical properties can be measured without changing the composition of matter:)
4 0
3 years ago
The purpose of an experiment is to determine if the _____ is correct or incorrect
Alexeev081 [22]

The purpose of an experiment is to determine if the hypothesis is correct or incorrect

<h3>What is an experiment?</h3>

An experiment is a research or test conducted in order to prove or disprove a hypothesis.

An experiment can also be done to answer a question.

A hypothesis is an answer provided to explain an observation without conducting tests to back up the explanation given.

Therefore, an experiment is aimed at determining if a hypothesis is correct or not.

Learn more about experiments at: brainly.com/question/17274244

#SPJ1

3 0
2 years ago
The specific reaction rate of a reaction at 492k is 2.46 second inverse and at 528k 47.5 second inverse.find activation energy a
crimeas [40]

Answer:

Ea = 177x10³ J/mol

ko = 1.52x10^{19} J/mol

Explanation:

The specific reaction rate can be calculated by Arrhenius equation:

k = koxe^{-Ea/RT}

Where k0 is a constant, Ea is the activation energy, R is the gas constant, and T the temperature in Kelvin.

k depends on the temperature, so, we can divide the k of two different temperatures:

\frac{k1}{k2} = \frac{koxe^{-Ea/RT1}}{koxe^{-Ea/RT2}}

\frac{k1}{k2} = e^{-Ea/RT1 + Ea/RT2}

Applying natural logathim in both sides of the equations:

ln(k1/k2) = Ea/RT2 - Ea/RT1

ln(k1/k2) = (Ea/R)x(1/T2 - 1/T1)

R = 8.314 J/mol.K

ln(2.46/47.5) = (Ea/8.314)x(1/528 - 1/492)

ln(0.052) = (Ea/8.314)x(-1.38x10^{-4}

-1.67x10^{-5}xEa = -2.95

Ea = 177x10³ J/mol

To find ko, we just need to substitute Ea in one of the specific reaction rate equation:

k1 = koxe^{-Ea/RT1}

2.46 = koxe^{-177x10^3/8.314x492}

1.61x10^{-19}ko = 2.46

ko = 1.52x10^{19} J/mol

3 0
3 years ago
Iupac name of h2so4<br>​
svlad2 [7]
Answer

Sulphuric Acid
8 0
3 years ago
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