An exothermic reaction releases 13,450J of heat. How many calories of energy are released? A) 5 56,274 calories B)1,244 caloriesC) 134,500 caloriesD) 3,215 calories

Answer:

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Answer:

D working alone

Explanation:

Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.

Choices A, B, and C are not correct because those are all good safety standards.

Answer:

Explanation:

Soap breaks up the oil into smaller drops, which can mix with the water. It works because soap is made up of molecules with two very different ends. One end of soap molecules love water - they are hydrophilic. The other end of soap molecues hate water - they are hydrophobic.

Answer:

C. Its polar end mixes with the water so it can be washed away.

Explanation:

Just took test

Answer:

natural selection

Explanation:

it is a biological selection of genes, whether dominant or negative.

Answer:

The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.

Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.

(Hope this helps) Sky

Answer:

increases

Explanation:

As the temperature of a fixed volume of a gas increases, the pressure will increase.

According to this law at constant volume of gas, pressure is directly proportional to the temperature of the gas and it is represented as:

P ∝ T.

It means that if pressure increases then temperature is also increases or if pressure decreases then temperature will also decreases.

So, pressure of the gas increases.

To know more about Gay Lussac's law, visit the below link:
https://brainly.com/question/24002551

Answer:

By using the speed of sound in water

Explanation:

(Which is about 1500 m/s in sea depending on the sea water density )

Answer:

Explanation:

Hb(CO)4(aq) + 4O2(g)  ⇄  Hb(O2)4(aq) + 4CO(g)

1 )  If we increase the concentration of CO(g) , the reaction above will proceed in reverse direction to decrease its concentration,  according to Le Chatelier principle. Hence more of Hb(CO)4(aq) will be formed.

2 )  If we decrease the concentration of O₂ , then also , reaction will proceed in reverse direction . Hence concentration of Hb(CO)4(aq) will be increased .

Answer:

True statements: B and C

Explanation:

A is not true NaCl is product

D is not true the reaction occurs

"Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides." - Wikipedia

Answer:

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Explanation:

Given:

Mass of copper (M) = 45 gram

Change in temperature (ΔT) = 71°C - 12°C = 59°C

Specific heat (c) =0.75 j /g*c

Find:

Heat energy (Q) = ?

Computation:

Heat energy (Q) = Mass(M) × Change in temperature (ΔT) × Specific heat (c)

Heat energy (Q) = 45 gram × 59°C × 0.75 j /g*c

Heat energy (Q) = 1991.25 J

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Winds are always named from the direction it blows from

Uneven heating of Earth's surface,in turn,causes differences in air pressure at various locations. Heated air rises,creating an area of low pressure beneath. Cooler air descends, creating an area of high pressure

Answer:

[tex]\large \boxed{\text{0.44 g}}[/tex]  

Explanation:

1. Calculate the molar mass of ammonia

1  N = 1 × 14.01    g = 14.01    g

3 H = 3 ×  1.008 g =  3.024     

                   TOTAL = 17.03   g

2. Calculate the mass of hydrogen

So, there are 3.024 g of H in17.03 g of NH₃.

The conversion factor is either

[tex]\dfrac{\text{3.024 g H}}{\text{17.03 g NH}_{3}} \text{ or } \dfrac{\text{17.03 g NH}_{3}}{\text{3.024 g H}}[/tex]

We want to find grams of H, so we choose the one with grams of H on top.

[tex]\text{Mass of H} = \text{2.5 g NH}_{3} \times \dfrac{\text{3.024 g H}}{\text{17.03 g NH}_{3}} = \textbf{0.44 g H}\\\\\text{The mass of H is $\large \boxed{\textbf{0.44 g}}$}[/tex]

Answer:

D. Wind Speed

Explanation:

When the question brings up 35 m/h, the m/h stands for Miles per Hour. What option can you measure the miles per hour. Here's a hint, it applies to cars as well when cops give your parents speeding tickets. Miles per Hour = Speed. So, you are measuring the wind speed.

Answer:

D. using a solid with a high surface area in the reactants, is your correct answer.

Explanation:

Using a solid with a high surface area in the reactants is usually associated with a higher reaction rate.

Answer:

b

Explanation:

it is right

Answer:

The correct answer is The pressure of the gas will increase

The volume of the gas will increase

Explanation:

Step 1: Data given

The gas in a container is heated, this means the temperature increases

Suppose we start with a temperature of 100 K and a pressure of 1 atm and a volume of 1L

Step 2:

V1/T1= V2/T2

⇒V1 = the initial  volume = 1L

⇒T1 = the initial temperature = 100 K

⇒V2 = the new volume = TO BE DETERMINED

⇒T2 = the increased temperature = 200 K

1/100 = V2 / 200

V2 = 2 L

This means when the temperature increases, the volume will increase

P1/T1 = P2/T2

⇒P1 = the initial pressure = 1 atm

⇒T1 = the initial temperature = 100 K

⇒P2 = the new pressure = TO BE DETERMINED

⇒T2 = the increased temperature = 200 K

1/100 = P2 / 200

P2 = 2 atm

This means when the temperature increases, the pressure will increase

The correct answer is The pressure of the gas will increase

The volume of the gas will increase

Answer:

Option C

Explanation:

Dipole moment being ac vector quantity has both magnitude and direction. All bonding forces have dipole moment ranging from partially positive to negative moment.  

Net dipole moment is the dipole moment arising after summation of all the existing dipole moments. On the basis of dipole moment it is determined whether the molecule is polar or non polar.  

Hence, option c is correct

Answer:c

Explanation:

Answer: c

Explanation: an xray wave does have a higher frequency than an infrared wave.

Answer:

Explanation:c

The biggest disadvantage of using nuclear power to produce electricity is the nuclear waste must be safely stored for many years.

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from:

Nuclear reactions produces high amount of energy and many waste materials which are non degradable and will stay in the environment for the long time.

Hence, nuclear waste must be safely stored for many years.

To know more about nuclear power, visit the below link:

https://brainly.com/question/11963586

#SPJ2

Answer:

0.479 M or mol/L

Explanation:

So Molarity is moles/litres of solution...often written as M=mol/L

So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2

Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L

Now we just plug these guys in our molarity formula M=mol/L

M= 0.3035/0.634 = 0.479 M or mol/L

Answer:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

Cl

, in calcium chloride, This will help you calculate the mass of chloride anions,

Cl

−

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

1

mole of calcium chloride contains

2

moles of chlorine atoms.

2

×

35.453

g mol

−

1

110.98

g mol

−

1

⋅

100

%

=

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

Cl

−

.

This implies that your sample contains

0.543

g CaCl

2

⋅

63.89 g Cl

−

100

g CaCl

2

=

0.3469 g Cl

−

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

⋅

0.3469 g Cl

−

500

mL solution

=

0.06938 g Cl

−

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

.

Explanation:

Answer:

all of them except number 2

Explanation:

Answer:

1,3,4,5  the other perosn is correct

Explanation: That what my quiz said

Answer:

A) number of electrons

Explanation:

A calcium atom has 20 electrons while a calcium ion has 18 electrons since it loses 2 electrons to form a stable octet structure. The formula of a calcium ion is Ca2+.

The number of protons does not change, neither do the number of neutrons. Atomic number is the proton number which is equals to the number of protons, hence B and C is wrong. Mass number is the number of protons and neutrons. Hence it doesnt change too and D is wrong.

Only the number of electrons change when an atom forms an ion.

Answer:98g/mol

Explanation:

Answer:

Should be A

Explanation:

Answer:it is D

Explanation: it is only one that makes sense

Answer:

The answer is NaOH

Explanation:

Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.

Answer:

NaOH

Explanation:

Got it right in the test. Please mark as brainliest

Answer:

1. sublimation

2.melting

3.melting  

4.sublimation

Explanation:

melting is a process when solid changes to liquid

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.