1. A positive value for AH for a chemical reaction is an indication of which of the following?
A. Reactants have higher potential energy and the reaction is endothermic.
B. Reactants have higher potential energy, and the reaction is exothermic.
C. Products have higher potential energy, and the reaction is endothermic.
D. Products have higher potential energy, and the reaction is exothermic.

Answer:

The choice that is not an indicator of a chemical change is "State of matter changes". More common than not, chemical reactions produce energy in the form of light or heat. Along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid).

Explanation:

The forces in gases are weaker than forces in solids and liquids.

Because they have more kinetic energy that overcomes the force of attraction.

Answer:

264 g/mol

Explanation:

#electrons equal #protons = 106

Plus 1 charge => m protons = 106 + 1 = 107

Mass number: 107 + 157 = 264 g/mol

it's 0.2cm different from the expected value, wich was 14.6cm

how many percent that are is calculated in the screenshot.

rounded it's 1.37%

Answer:

The halogen is Iodine.

Explanation:

Using the ideal gas equation, we find the number of moles of gas present, n.

PV = nRT where P = pressure of gas = 1.41 atm, V = volume of gas = 109 mL = 0.109 L, n = number of moles of gas, R = molar gas constant = 0.082 L-atm/mol-K and T = temperature of gas = 398 K

Since PV = nRT, making n subject of the formula, we have

n = PV/RT

substituting the values of the variables into the equation, we have

n = 1.41 atm × 0.109 L/(0.082 L-atm/mol-K × 398 K)

n = 0.15369 atm-L/32.636 L-atm/mol

n = 0.0047 mol

Since n = m/M where m = mass of gas = 1.19 g and M = relative molecular mass of gas

So, M = m/n

M = 1.19 g/0.0047 mol

M = 252.7 g

Since halogens are diatomic the relative atomic mass is M/2 = 252.7g/2 = 126.34 g

From tables, the only halogen with this atomic mass is Iodine.

So, the halogen is Iodine.

gasoline is the chemical that is coming out of the air

Answer:

because the have stronger electrostatic force

Answer:

There are 1.195 calories in 5 J.

Explanation:

The relation between calorie and Joules is as follow :

4.184 J = 1 calorie

or

1 J = (1/4.184) calorie

Let the taken number is 5 J

So,

5 J = (5/4.184) calorie

5 J = 1.195 calorie

So, there are 1.195 calories in 5 J.

Answer:

Nitrate NO3

here's your answer, hope it helps you

Answer:

0.2762M Na+ in the solution

Explanation:

2.07g of sodium iodide Is Dissolved In 50.ML Of A 0.30M...

To solve this question we need to find the moles of sodium iodide, NaI, that are the same than the moles of sodium cation, Na+. The volume in liters of the solution is 0.050L. The molarity is:

Moles NaI = Moles Na+ -Molar mass NaI: 149.89g/mol-

2.07g NaI * (1mol / 149.89g) = 0.01381 moles NaI = Moles Na+

Molarity:

0.01381 moles Na+ / 0.0500L =

0.2762M Na+ in the solution

Answer:

c. CH3CH2CH(CH3)CHO

Explanation:

Hello there!

In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:

[tex]CH_3CH_2CH(CH_3)CH_2OH\rightarrow CH_3CH_2CH(CH_3)COH[/tex]

Regards!

Answer: 3.4 × 10 -1 equal 33.5 cs. May I have brainiest? pls. (the -1 is to the power of the ten.

Answer:

d

Explanation:

Answer:

answer = 22.5m

Explanation:

using

[tex]s = \frac{ {v}^{2} - {4}^{2} }{2a} [/tex]

s= (0²-21²)/2(-9.8)

s= -441/19.6

s= 22.5m

do consider marking as Brainliest if this helped!!

Answer:

Mass CO2 = 3.75 grams

Mass H2O = 2.30 grams

Mass SO2 = 2.73 grams

Explanation:

Step 1: Data given

Density of Liquid ethyl mercaptan, C2H6S = 0.84 g/mL

Volume of ethyl mercaptan = 3.15 mL

Step 2: The reaction

2C2H6S + 9O2 → 4CO2 + 6H2O + 2SO2

Step 3: Calculate mass of ethyl mercaptan

Mass = Volume * density

Mass ethyl mercaptan = 3.15 mL * 0.84 g/mL

Mass ethyl mercaptan = 2.646 grams

Step 4: Calculate moles ethyl mercaptan

Moles = mass / molar mass

Moles ethyl mercaptan = 2.646 grams / 62.13 g/mol

Moles ethyl mercaptan = 0.04259 moles

Step 5: Calculate moles of other products

For 2 moles ethyl mercaptan we need 9 moles O2 to produce 4 moles CO2, 6 moles H2O and 2 moles SO2

For 0.04259 moles we need 0.1917 moles O2 to produce:

2*0.04259 = 0.08518 moles CO2

3*0.04259 = 0.1278 moles H2O

1*0.04259 = 0.04259 moles SO2

Step 6: Calculate mass produced

Mass = moles * molar mass

Mass CO2 = 0.08518 moles * 44.01 g/mol

Mass CO2 = 3.75 grams

Mass H2O = 0.1278 moles * 18.02 g/mol

Mass H2O = 2.30 grams

Mass SO2 = 0.04259 moles * 64.07 g/mol

Mass SO2 = 2.73 grams

Answer:

There are four containers: a 100-mL beaker, 250-mL Erlenmeyer flask, a 500-mL beaker, and a 1-L Florence flask. They contain coffee, tea, water, and milk, although not in that order. Use the following facts to identify the beverage in each container.

a. the 500-mL container has a beverage commonly associated with breakfast.

b. the largest container has a colorless liquid (i.e. neither yellow nor orange).

c. the beverage in the smallest container is opaque. (you cannot see through it).

d. One clear liquid is in a container half the volume of a colored liquid.

e. The only combustible liquid has exactly twice the volume of an opaque liquid.

Explanation:

a. The 500-mL container has a beverage commonly associated with breakfast is coffee.

b. The largest container has a colorless liquid (i.e. neither yellow nor orange) water.

c. The beverage in the smallest container is opaque. (you cannot see through it) milk.

d. One clear liquid is in a container half the volume of a colored liquid tea.

The 500-mL container has a beverage commonly associated with breakfast is coffee. (rest answers are as follows)

The Indentification of the beverages can be done by knowing the content and optical activity that uniquely identify the container.

Learn more about optical activity here ;

https://brainly.com/question/15892094

#SPJ5

Answer:

second law of thermodynamics

Explanation:

According to the second law of thermodynamics, the total entropy of a system and its surroundings always increases for a spontaneous process.

Entropy is defined as the degree of disorderliness of a system. The entropy of a system never remains constant. It either increases or decreases in a process. The total entropy is the sum of the entropy of the system and its surrounding. The total entropy must increase in a spontaneous process.

Thus, the implication of this law is that even, if the entropy of a system decreases, this must be compensated for by increase in entropy of the surroundings in order for the process to be spontaneous.

Answer:

this answer is for first one

Explanation:

A higher evalations, where the atmospheric pressure is much lower, the boiling point increase with increased pressure up to the critical point where the gas and liquid properties become identical

Answer:

"1.4 mL" is the appropriate solution.

Explanation:

According to the question,

Now,

Increase in volume will be:

⇒ [tex]\Delta V = \alpha\times v_0\times \Delta \epsilon[/tex]

By putting the given values, we get

           [tex]=1.12\times 10^{-4}\times 500\times 25[/tex]

           [tex]=1.12\times 10^{-4}\times 12500[/tex]

           [tex]=1.4 \ mL[/tex]

Answer:

The general preparation of esters( for example ethyl ethanoate) is through a process known as ESTERIFICATION.

Explanation:

The formation of an ester by the reaction between an alkanol and an acid is known as esterification. This reaction is extremely slow and reversible at room temperature, and is catalyzed by a high concentration of hydrogen ions.

In the preparation of one of the simpler esters known as ETHYL ETHANOATE the reactants include ethanol(an alcohol) and glacial ethanoic acid(a carboxylic acid) in the presence of concentrated tetraoxosulphate VI acid as a CATALYST. Note that, a catalyst is any substance that is able to increase the rate of a chemical reaction.

The mixture is warmed in a water bath( hot but not boiling) for about 25 minutes. The mixture is poured into a beaker partially filled with a sodium or calcium chloride to remove interacted ethanol. The ethyl ETHANOATE floats on the mixture as oily globules.

Answer:

7.44 C is the answer of the question.

Explanation:

Answer:

Theory

Explanation:

We are given the statement;

"A helium filled balloon floats."

Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.

Thus, the statement in the question is a theory.

Answer:

3-hexanol

1 -butanol

2-pentanol

Explanation:

Let us recall that chromic acid or chromate are strong oxidizing agents. When they are oxidized, their colour changes from orange to green.

This shows a reduction in chromic acid or chromate. The reaction of chromic acid or chromate with a primary alcohol yields a carboxylic acid while reaction with a secondary substrate yields an alkanal.

Note that Tertiary alkyl halides are not be oxidized hence reactions involving a point where invitation carried along occur.

3-ethyl-3-pentanol is a tertiary alkyl halide hence it can not be oxidized.

Explanation:

mass=kilogram (kg)

temperature=kelvin

power=watt

hope it helps

Answer:

See explanation

Explanation:

Since we have to fill five subshells in moving from Og to the next noble gas in the eight period, we have to know the maximum electrons contained in each of those subshells;

s= 2, p=6, d= 10, f= 14, g = 18

This means that we need a total of 50 electrons to fill all the five subshells.

Hence, the element just below Sg in the eight period will have an atomic number of 156.

Answer:

less than 5 centimeters because it is a nonvascular plant

Explanation:

Mosses are a group of plants under the division Bryophyta. They are said to be the most primitive plant life in existence as they lack true roots, stems and leaves. They also lack vascular system, hence, they are regarded as non-vascular plants. They usually grow in very small sizes (about 0.2 - 10cm).

According to this question, Penny bought a club moss plant for her water garden and needs to know how tall the plant will grow so she know how much space it will need. Since it is a miss plant that lacks vascular tissues i.e. nonvascular, it will likely grow less than 5 centimeters in height.

Answer:

d

Explanation:

Answer: The moles of gas present in the cylinder is 0.34 moles.

Explanation:

Given: [tex]P_{1}[/tex] = 2.7 atm,   [tex]V_{1}[/tex] = 3.1 L,     [tex]T_{1}[/tex] = 300 K

[tex]P_{2}[/tex] = ?,      [tex]V_{2}[/tex] = 9.4 L,       [tex]T_{2}[/tex] = 610 K

Formula used to calculate the final temperature is as follows.

[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]

Substitute the values into above formula as follows.

[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{2.7 atm \times 3.1 L}{300 K} = \frac{P_{2} \times 9.4 L}{610 K}\\P_{2} = \frac{5105.7}{2820} atm\\= 1.81 atm[/tex]

Now, moles present upon heating the cylinder are as follows.

[tex]P_{2}V_{2} = n_{2}RT_{2}\\1.81 atm \times 9.4 L = n_{2} \times 0.0821 L atm/mol K \times 610 K\\n_{2} = \frac{17.014}{50.081} mol\\= 0.34 mol[/tex]

Thus, we can conclude that moles of gas present in the cylinder is 0.34 moles.

Answer:

2 Cu + O2 → 2 CuO

This is an oxidation-reduction (redox) reaction:

2 Cu0 - 4 e- → 2 CuII

(oxidation)

2 O0 + 4 e- → 2 O-II

(reduction)

Cu is a reducing agent, O2 is an oxidizing agent.

Refer to the attachment.

Hope this helps you...