what is a substance?
Please help with this
An atom has 13 protons, 14 neutrons, and 10 electrons. What element is this atom? How did you determine which element it was?
Benzoic acid contains 68.8% carbon, 4.95% hydrogen, and 26.25% oxygen. Find the empirical formula of benzoic acid.
Answer:
C7H6O2
Explanation:
Let;
68.8% of Carbon represents 68.8g
4.95% of Hydrogen represents 4.95g
26.25% of Oxygen represent 26.25g
Next, we convert each gram value to mole value by dividing by their respective molar mass {C = 12, H = 1, O = 16}
C = 68.8/12 = 5.73 mol
H = 4.95/1 = 4.95 mol
O = 26.25/16 = 1.64 mol
Next, we divide each mole value by the smallest (1.64mol)
C = 5.73 ÷ 1.64 = 3.49
H = 4.95 ÷ 1.64 = 3.02
O = 1.64 ÷ 1.64 = 1
Next, we multiply each ratio by 2 to obtain our simplest whole number ratio (empirical formula)
C = 3.5 × 2 = 7
H = 3.02 × 2 = 6
O = 1 × 2 = 2
Hence, the ratio of C, H and O is 7:6:2 and the empirical formula of benzoic acid is C7H6O2
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Sierra has a special kind of liquid rubber. She knows that ultraviolet light is absorbed by the rubber, X-ray light is transmitted through the rubber, and blue light is reflected off the rubber. Sierra wonders if the liquid rubber will become solid if she shines the lights on it. Can light cause the rubber to become solid? Why or why not? Does it matter what type of light she shines on the rubber?
Answer:
yes it can because heat can solidify the rubber and it does matter what light
Explanation:
The light can cause the rubber to become solid. It doesn't matter the type of light.
Any type of light can cause the rubber to become solid because all types of
light emit thermal(heat) radiation. When they are emitted , it causes the
vaporization of some compounds thereby causing it to solidify.
In this scenario, the rubber being able to absorb ultraviolet light simply
depicts that it will solidify as a result of an increase in temperature due to
the thermal radiation.
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a primary means of conveying messages between human
Answer:
The primary means of conveying messages between human are verbal, nonverbal, and visual.
Explanation:
1. Verbal communication depends on words to deliver meaning.
2. Nonverbal communication occurs when meaning or messages are sent or received without the use of words.
3. Visual communication utilizes drawings, illustrations, pictures, colors, graphs, charts, and signs to share meaning.
The verbal method of talking is the primary means of conveying messages among humans.
What makes speaking possible?Speech is spoken language used by people to communicate. The ability to modify voices through the articulation of laryngeal tones into audible oral speech is something that humans have learnt to do, despite the fact that many animals have voices of varied sorts and inflectional capacities.
A bellows-like respiration activator, which provides the driving energy in the shape of an updraft, a phonating sound generator in the larynx (low in the throat), to transform the energy, an audio tunable in the pharynx (higher in the throat), where the independent voice structure is moulded, and a speech-forming device that is connected in the oral cavity represent as the mechanisms for human speech (mouth).
The four structures usually, but not always, work closely together. Toneless whispering can provide audible communication without any voice, and some parts of yodelling that depend on pharyngeal and laryngeal alterations can produce phonation without oral articulation. Lipreading may be accomplished by silent articulation without voice or breath.
Therefore, speech is the primary method of communication among humans.
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The air in a living room has a mass of 60 Kg and a specific heat of 1,020 J/kg°C. What is the change in thermal energy of the air when it warms from 20°C to 25°C?
Answer:
Q = 306 kJ
Explanation:
Given that,
Mass, m = 60 kg
Specific heat, c = 1020 J/kg°C
The temperature changes from 20°C to 25°C.
Let Q be the change in thermal energy. The formula for the heat released is given by :
[tex]Q=mc\Delta T[/tex]
Put all the values,
[tex]Q=60\times 1020\times (25-20)\\\\Q=306000\ J\\\\or\\\\Q=306\ kJ[/tex]
So, 306 kJ is the change in thermal energy.
Static electricity happens when electrons pass from one object to another, such as from your hair to a comb as you comb your hair. If you were to comb your hair and then hold the comb near your hair, strands of hair would move forward and appear to stick to the comb. How could the interaction between the hair and the comb be described?
They repel each other because they have opposite charges.
They repel each other because they have the same charges.
They attract each other because they have opposite charges.
They attract each other because they have the same charges.
How many atoms are in 25.00 g of B?
A. 1.393 x 10^24 atoms of B
B. 1.333 x 10^23 atoms of B
C. 2.16 x 10^26 atoms of B
D.217 x 10^24 atoms of B
Thanks for all the efforts :)
Answer:
There are 1.393 x 10²⁴ atoms in 25.00 g of B.
Explanation:
Hey there!
We are given a value, in grams, that we need to convert to a number of atoms.
We can convert grams to atoms by using Avogadro's Number ([tex]N_A[/tex]). This number is equivalent to [tex]6.022 \times 10^{23}[/tex].
This number can be used to convert any values to:
atomsmoleculesformula unitsmolesIn order to do this problem, we will need to use dimensional analysis (DA). This process allows us to convert from grams to atoms.
We need to set up our ratios in order to work this out. We can use a periodic table to help us through this next part of the problem.
1. Locating the number of moles of B in the sample
We first need to find the amount of moles of boron (B) there are in the sample.
Checking a periodic table, the atomic mass in atomic mass units (amu) is 10.81 amu.
Atomic mass units can easily be converted to grams and these units can be used interchangeably.Therefore, for each atom of boron, it weighs 10.81 grams to us. This is equivalent to the mass of one mole of boron.
To find the number of moles, we have two possible ratios we can use:
[tex]\displaystyle \frac{1 \ mole \ B}{10.81 \ grams \ B}[/tex][tex]\displaystyle \frac{10.81 \ grams \ B}{1 \ mole \ B}[/tex]These ratios mean the same thing, but we need to convert our final unit to moles.
We are given a sample in grams, and when dividing our units, we need to keep moles.
Since the first portion of our expression is in grams, we need to have grams in the bottom of our expression.
[tex]\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}}[/tex]We can now simplify the expression. Our grams B unit will cancel out, so we are therefore left with moles B remaining.
2. Locating the number of atoms in the sample
Now with our equation, we can convert our number of moles that would be solved if we stopped with the above. However, we need to convert to atoms.
We use Avogadro's number and create a ratio with that of moles.
[tex]\displaystyle \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}[/tex][tex]\displaystyle \frac{1 \text{mole B}}{6.022 \times 10^{23} \text{atoms}}[/tex]We need to cancel out our moles and end with atoms, so we must have moles in the denominator. Therefore, we use the first ratio.
Using our previous expression, we multiply by this new ratio and solve the expression.
[tex]\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}} \ \times \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}[/tex]This expression can now be operated. You will need a calculator to perform this calculation.
Our numerator is:
[tex][(25.00 \times 1 \times (6.022 \times 10^{23})][/tex]Plugging this into a calculator, we get:
[tex]1.5055 \times 10^{25}[/tex]Our denominator is:
[tex](1 \times 10.81 \times 1)[/tex]This simplifies to:
[tex]10.81[/tex]Dividing our numerator and denominator:
[tex]\displaystyle \frac{1.5055 \times 10^{25}}{10.81}[/tex]Plugging this into a calculator, we get:
[tex]1.392691952 \times 10^{24}[/tex]3. Simplifying with significant figures
Now, we need to take into account that we have significant figures. We are given this original value:
[tex]25.00[/tex]This value has four significant figures, which means we need to round our value we received above to four significant figures.
[tex]\approx 1.393[/tex]Our units are added as well as our scientific notation:
[tex]1.393 \times 10^{24} \ \text{atoms of B}[/tex]Therefore, our final answer is choice A.
Ideal gas law:
If 6.3 moles of a gas in a 20 L cylinder have a pressure of 5.5 atm, what is the temperature?
Answer:
212. 9 degree celcius
Explanation:
From PV =nRT
T= PV/nR
T= (5. 5x20)/(6. 3x0. 082)
T= 110/0. 5166
T= 212. 9 degree celcius
2A + N2 -> 2AIN How many moles of aluminum nitride form when 5.00 g of aluminum reacts with excess nitrogen? K 0.0925 mol 0 0.185 mol Oleo mol z se mol
Answer:
0.185 moles of AlN
Explanation:
The equation is:
2Al + N₂ → 2AlN
This reaction indicates that 2 mol of aluminum can react to 1 mol of nitrogen to produce 2 moles of aluminum nitride.
We convert the aluminum's mass to moles
5 g/ 26.98 g/mol = 0.185 moles.
2 moles of Al are needed to produce 2 moles of AlN
so, ratio is 1:1
In conclussion we say:
0.185 moles of Al, must produce 0.185 moles of AlN
CH=C-CH=CH– CH = CH, what is the name of this molecule?
Answer:
pent-3-ene-1-yne
Explanation:
1 2 3 4 5
CH ≡ C - CH = CH - CH3
IUPAC name : Pent-3-ene-1-yne
How many grams are there in 51.9 moles of F2 gas? (4 pts)
PLS HELP ASAP ILY
Answer:
1972 grams of F₂
Explanation:
Multiply the molar mass of F₂ by the number of moles
One molecule of a compound weighs 2.93 10–22 g. The molar mass of this compound is:
A)
2.06 g/mol
B)
567 g/mol
C)
168 g/mol
D)
176 g/mol
E)
none of these
Answer:
176 g/mol
Explanation:
To get this, multiply the weight of the molecule by Avogadro's number:
(2.93×[tex]10^{-22}[/tex]) × (6.022×[tex]10^{23}[/tex]) = 176.44 g/mol
Lower the Room temp. to -10.0 °C, wait until all the water has frozen, and then wait a little while more. What happens to the ice temperature after all the water is frozen?
No link or Files Plzz
Answer:
the ice becomes -20 degrees celcius colder
Explanation:
What is the relative humidity if the dry bulb temperature is 16°C and the wet bulb temperature is 16°C?
what’s the answer to number 6 ty!!
Answer:
0.00032 M
Explanation:
From the question,
Applying the for pH
pH = -log[H⁺]............... Equation 1
Where H⁺ = Hydrogen ion concentration of Hydrochloric acid
Given: pH = 3.50
Substitute into equation 1 and solve for H⁺
3.50 = -log[H⁺]
Taking the log inverse of both side,
H⁺ = 10⁻⁽³⁵/¹⁰⁾
H⁺ = 0.00032 M
Hence the H⁺ of Hydrochloric acid is 0.00032 M
1. What is the molar mass of sodium?
11
O
45.90
23
О
16
Answer:
11
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11.
Answer:
22.99g/mol (in this case 23g/mol)
B.Use the words inside the box to complete the chart below
Answer:
Answered below
Explanation:
>> ice is solid
>> water is liquid
>> Steam is gas
>> Ice → water = melting
>> water → steam = evaporation
>> steam → water = condensation
>> water → ice = freezing
You’re going on a plane from Alaska to Florida and you’re taking your bike. It’s the middle of the winter. You fill up your tires before you leave to a pressure of 4.72 atm on a day that is -3.50°C. When you arrive in FL at 42°C, you check the pressure in your tires before you ride and find the pressure to be:
Answer:
5.52atm
Explanation:
Using the pressure law formula:
P1/T1 = P2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the question, the following information were provided;
P1 = 4.72 atm
P2 = ?
T1 = -3.50°C = -3.50 + 273 = 269.5K
T2 = 42°C = 42 + 273 = 315K
Using P1/T1 = P2/T2
4.72/269.5 = P2/315
CROSS MULTIPLY
4.72 × 315 = 269.5 × P2
1,486.8 = 269.5P2
P2 = 1,486.8 ÷ 269.5
P2 = 5.52atm
what element has the same amount of valence electrons as neon?
-KDM
Answer:
Sulfur has the same amount, like all the other elements in group 16, has six valence electrons.
Explanation:
Answer:
give me the question and I can help you
Which factor is included in the ideal gas law that isn't present in the others?
Number of moles
Explanation:
From the general formula of ideal gas equation it is seen that number of moles is present and absent in other gas equations
Which substance is a binary acid?
1,)hydrochloric acid
2.)phosphoric acid
3.)nitrous acid
4.)sulfuric acid
Answer:
1. Hydrochloric acid
Explanation:
Hydrochloric acid
Answer:
4)
Explanation:
formula:H2 SO4
there are 2 H+ ions in 1 molecule of sulfuric acid
thus it has a basicity of 2
Identify the element whose ion can exist as 2+ or 4+?
A) Sodium
B) Lead
C) Sulfur
D) Calcium
8. (a) What is an acid-base indicator?
Answer:
Acid–base indicators are generally weak protolytes that change color in solution according to the pH. The acid–base equilibrium of a weak acid type of indicator (HI) in water can be represented as. [I] The acid, HI, and the conjugate base, I−, have different colors. The equilibrium expression for this process is.
Explanation:
9. A student needs to prepare 100 mL of a 0.50 M ammonium chloride, NH4Cl,
solution. How much solute does he need?
Answer:
2.67g of NH4Cl are required
Explanation:
Molarity is an unit of concentration in chemistry defined as the moles of solute (In this case, NH4Cl), per liter of solution.
To prepare 100mL of a 0.50M are required:
100mL = 0.100L * (0.50 moles / L) = 0.0500 moles NH4Cl
As molar mass of NH4Cl is 53.491g/mol:
0.0500 moles * (53.491g / mol) =
2.67g of NH4Cl are requiredTyler is running down the street after his brother at a speed of 1.2 m/s and contains 10.8 J of kinetic energy. Calculate Tyler’s mass
Answer:
I do not know
Explanation:
I am vert sorry but I do not know the answer.
Climate change is ONLY caused by human activities
OTrue
O False
Answer:
That is False
Explanation:
That is false because climate change happen due to Wind, rainfall etc
Is a flashlight turned on kinetic or potential energy ?
Which is not a physical state of matter?
A. Solid
B. Liquid
C. Plasma
D. Gas
Answer: Plasma
Explanation:
Answer: Plasma
Explanation: