Answer:
7.6Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ {H}^{+} ][/tex]
From the question we have
[tex]ph = - log(2.5 \times {10}^{ - 8} ) \\ = 7.60205[/tex]
We have the final answer as
7.6
Hope this helps you
what is the part of the earth that is made up of the crust and upper mantle
The crust + upper mantle is called the lithosphere.
At a certain temperature the vapor pressure of pure benzene is measured to be . Suppose a solution is prepared by mixing of benzene and of heptane . Calculate the partial pressure of benzene vapor above this solution. Round your answer to significant digits.
Answer:
P(C₆H₆) = 0.2961 atm
Explanation:
I found an exercise pretty similar to this, so i'm gonna use the data of this exercise to show you how to do it, and then, replace your data in the procedure so you can have an accurate result:
"At a certain temperature the vapor pressure of pure benzene (C6H6) is measured to be 0.63 atm. Suppose a solution is prepared by mixing 79.2 g of benzene and 115. g of heptane (C7H16) Calculate the partial pressure of benzene vapor above this solution. Round your answer to 2 significant digits. Note for advanced students: you may assume the solution is ideal".
Now, according to the data, we want partial pressure of benzene, so we need to use Raoul's law which is:
P = Xₐ * P° (1)
Where:
P: Partial pressure
Xₐ: molar fraction
P°: Vapour pressure
We only have the vapour pressure of benzene in the mixture. We need to determine the molar fraction first. To do this, we need the moles of each compound in the mixture.
To get the moles: n = m / MM
To get the molar mass of benzene (C₆H₆) and heptane (C₇H₁₆), we need the atomic weights of Carbon and hydrogen, which are 12 g/mol and 1 g/mol:
MM(C₆H₆) = (12*6) + (6*1) = 78 g/mol
MM(C₇H₁₆) = (7*12) + (16*1) = 100 g/mol
Let's determine the moles of each compound:
moles (C₆H₆) = 79.2 / 78 = 1.02 moles
moles (C₇H₁₆) = 115 / 100 = 1.15 moles
moles in solution = 1.02 + 1.15 = 2.17 moles
To get the molar fractions, we use the following expression:
Xₐ = moles(C₆H₆) / moles in solution
Xₐ = 1.02 / 2.17 = 0.47
Finally, the partial pressure is:
P(C₆H₆) = 0.47 * 0.63
P(C₆H₆) = 0.2961 atmHope this helps
Please help!
When a 200.0 g block of iron is placed into 1500.0 g of water, the temperature of the iron increases by 50.0 °C. The specific heat of iron is 0.449 J/g^ C . What is the temperature change of the water? (0.715 C)
Thank you!
Answer:
[tex]\Delta T_{w}=-0.715\°C[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible to realize that the heat relationship between iron and water is given by:
[tex]-Q_{Fe}=Q_{w}[/tex]
Which in terms of mass, specific heat and temperature is:
[tex]-m_{Fe}C_{Fe}\Delta T_{Fe}=m_{w}C_{w}\Delta T_{w}[/tex]
Thus, by solving for the change in the temperature of water we will obtain:
[tex]\Delta T_{w}=\frac{-m_{Fe}C_{Fe}\Delta T_{Fe}}{m_{w}C_{w}} \\\\\Delta T_{w}=\frac{-200.0g*0.449\frac{J}{g\°C} 50.0\°C}{1500.0g4.184\frac{J}{g\°C}} \\\\\Delta T_{w}=-0.715\°C[/tex]
Which is negative because iron increases its temperature and therefore water decreases it.
Regards!
Which of the following is true for a gas under conditions of very high pressure? (5
points)
1) PV > nRT, because the real volume of the gas would be more than the ideal
volume.
2) PV = nRT, because intermolecular forces are considerable at very high
pressures.
3) PV = nRT, because all gases behave as ideal gases at very high pressures.
04) PV = nRT, because the volume of the gas would become negligible.
Answer:
1) PV > nRT, because the real volume of the gas would be more than the ideal
volume.
Explanation:
According to the ideal gas equation; PV = nRT. Let us recall that this equation only holds under ideal conditions.
Gases exhibit ideal behavior under high temperature and low pressure. At higher pressure, the real volume of the gas is larger than the ideal volume of the gas.
Thus, at high pressure, PV > nRT, because the real volume of the gas would be more than the ideal volume.
Answer:
1) PV > nRT, because the real volume of the gas would be more than the ideal volume.
Explanation:
just took the test :)
The specific heat capacity of liquid water is 4.18 J/g oC. Calculate the quantity of energy required to heat 1.50 g of water from 26.5oC to 83.7oC. (Ignore significant figures for this problem.)
Answer: The quantity of heat required is 358.644 J.
Explanation:
Given: Specific heat capacity = [tex]4.18 J/g^{o}C[/tex]
Mass = 1.50 g
[tex]T_{1} = 26.5^{o}C[/tex]
[tex]T_{2} = 83.7^{o}C[/tex]
Formula used to calculate heat energy is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\= 1.50 \times 4.18 J/g^{o}C \times (83.7 - 26.5)^{o}C\\= 358.644 J[/tex]
Thus, we can conclude that quantity of heat required is 358.644 J.
In a physical change the make up of matter is changed.
O True
O False
Answer:
yes it is true
Explanation:
evaporation occurs when burning liquid water changes into gas.
give an example of a primary income from the rest of the world
Answer:
(1) Income Associated with the Production Process
(a) Compensation of employees
(b) Taxes and subsidies on products and
production .
(2) Property Income
(a) Investment income:
• Dividends and withdrawals from income of
quasi-corporations
• Reinvested earnings
• Interest
(b) Rent .
I hope this is correct :-)
How much heat must be absorbed by 375 grams of water to raise its temperature by 25 degrees Celsius? Specific heat for water= 4.184 J/g/C or K
Answer:
[tex]3.9*10^4 J[/tex]
Explanation:
See image for explanation!Answer:
[tex]\boxed {\boxed {\sf 39, 225 \ Joules}}}[/tex]
Explanation:
Since we are given the mass, temperature, and specific heat, we should use the following formula to calculate heat energy.
[tex]q=mc \Delta T[/tex]
We have 375 grams of water, the specific heat of water is 4.184 J/g ° C, and the temperature is raised 25 degrees Celsisus. Therefore:
m= 375 g c= 4.184 J/g °C ΔT= 25°CSubstitute the values into the formula.
[tex]q= (375 \ g)(4.184 \ J/g \textdegree C)(25 \textdegree C)[/tex]
Multiply the first two values together. The units of grams will cancel.
[tex]q=1569 \ J/ \textdegree C(25 \textdegree C)[/tex]
Multiply again. This time, the degrees Celsius cancel, so we are left with only the units of Joules.
[tex]q= 39225 \ J[/tex]
39,255 Joules of heat must be absorbed by the water.
What number should be written in front of Na to balance the equation?
Na + MgCl2 → NaCl + Mg
1
2
3
4
In order to balance the chemical equation, the coefficient of Na should be 2.
Examine the map of the United States. Tornadoes are most common in the Midwest and Great Plains states. According to the map, what causes the prevalence of tornadoes in these regions? A) Falling air currents form from the mixing of falling warm, moist air and the rising of cold air. B) Spinning air currents form from the mixing of rising warm, moist air and the falling of cold air. C) Spinning air currents form when cold, dry air becomes saturated with moisture and becomes unstable. Eliminate D) Rising air currents form from the deposition of cold air at the surface and moist air at the top of the troposphere.
Answer:
the answer is B-Spinning air currents form from the mixing of rising warm, moist air and the falling of cold air.
Explanation:
Question 5 (5 points)
Complete the following sentences:
a)
is the least reactive alkall metal.
b)
is the most reactive alkali metal.
is the least reactive alkaline earth metal.
d)
is the most reactive alkaline earth metal.
e)
is the most reactive halogen
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Blank 2:
Blank 3:
Blank 4:
Blank 5:
Question 6.12
I need guidance on this question
Answer:
(C) NO2 has covalent bonds.
Octane (C8H18) is found in gasoline. It is burned for fuel in a combustion
reaction. The unbalanced combustion reaction for octane is shown below.
C8h18+ O2 → C02 + H2O + heat
When the reaction is balanced, how many carbon dioxide molecules are
produced for every octane molecule burned?
Answer:
Explanation:
It's 8
How many moles are in 3.72 x 10^27 atoms of iron?
Answer: There are [tex]0.617 \times 10^{4}[/tex] moles present in [tex]3.72 \times 10^{27}[/tex] atoms of iron.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] atoms present in one mole of a substance.
Hence, moles present in [tex]3.72 \times 10^{27}[/tex] atoms are calculated as follows.
[tex]Moles = \frac{3.72 \times 10^{27}}{6.022 \times 10^{23}}\\= 0.617 \times 10^{4} mol[/tex]
Thus, we can conclude that there are [tex]0.617 \times 10^{4}[/tex] moles present in [tex]3.72 \times 10^{27}[/tex] atoms of iron.
Over a period of 30 days a student studied the night sky and recorded his observations. One night he watched a shooting star streak across the sky. His curiosity led him to list all the possible things it could be, then after researching, analyzing and comparing each, he proposed that which of the following was the most logical identification of a "shooting star? Answer F asteroid G comet H meteor J moon
Answer:
meteor
Explanation:
The most logical identification of a "shooting star" is a meteor. A meteor is basically any material from outerspace that falls to Earth. The main characteristic of a meteor is that from our point of view on the surface of the Earth it looks like a shooting star because we see a streak of light behind it. This light is simply dust and rock from the meteor burning up as it enters the Earth's atmosphere, leaving a "tail" of light behind it. Which to us looks like a shooting star.
An analysis of a compound shows that it consists of 36.8% nitrogen and 63.2% oxygen
Answer:
This question is incomplete, however, it is asking to calculate the empirical formula of the compound.
The empirical formula is N2O3
Explanation:
The following information about a compound was got from the question:
N = 36.8%
O = 63.2%
It can be said that the compound contains 36.8g of nitrogen (N) and 63.2g of oxygen (O).
Next, we convert each mass composition to moles by dividing by their respective molar masses.
N = 36.8g ÷ 14g/mol = 2.628mol
O = 63.2g ÷ 16g/mol = 3.95mol
Next, we divide each mole value by the smallest value (2.628mol).
N = 2.628mol ÷ 2.628 = 1
O = 3.95mol ÷ 2.628 = 1.5
We multiply each value by 2 to get a empirical ratio.
N = 2
O = 3
The ratio of N:O is 2:3, hence, the empirical formula is N2O3.
A community located downwind from a coal-fired power plant has seen a recent increase in the number of dead and dying trees. A so scientist measured values for the following parameters before and after the trees died off. Which of the following oil data should be used to determine if the coalfired power plant emiations were the cause of the damage to the trees
a. Moisture content and water retention
b. Parent material composition
c. Pesticide and herbicide residue levels
d. Calcium and aluminum levels
Answer:
Option D, Calcium and Aluminum levels
Explanation:
The coal fired power plant releases huge amount of particulate and gaseous emissions such as mercury, sulphur dioxide, nitrogen oxide etc. When there is rain, these gaseous and particulate matter comes to the ground along with rain water and pollute the soil. There are also chances of acid rain due to the presence of sulphur dioxide. Polluted soil and acid rain negatively impact the growth of the plants and causes leaching of Aluminium thereby decreasing the availability of calcium for the plants. Thus, the trees die. Hence, if the amount of Aluminium and Calcium in soil is determined, one can easily deduce the cause of death of trees.
Hence, option D is correct
The exact mechanism of this reaction is a little complicated, as it involves the copper ions. However, the process involves the formation of small amounts of bromine in situ. Draw the mechanism of the bromination of 4-tert-butyl phenol with Br2. -g
Answer:
see picture below
Explanation:
The mechanism is in the following picture.
In the first step, the lone pair of oxygen (from the OH) as it's a strong activating group in the molecule, will go to the ring. This will cause that the double bond of the ring of the ortho position, attacks as nucleophyle to the Br2, causing the breaking of the bond.
In the second step, the bromine ion substract the hydrogen from the ortho position, and then, by resonance, the pair of electrons returns to the oxygen of the phenol.
Give the ratio that balances out the following equation: ___Cr + ___Pb(NO3)4 ---> ___ Cr(NO3)3 + ____ Pb
Answer: Ratio : 4, 3, 4, 3 are the answers.
Explanation:
А is a living thing that eats other dead things.
Answer:
Scavengers
Explanation:
How many moles of Carbon can be made from 6.37 moles of Iron?
Answer:
Percent yield = 57.7 %Explanation:
What compound(s) does pure water contain?
what do adamantium,vibranium and unobtainum have in common
Answer:
they're all fake
Explanation:
in writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is
a.H
b.2H
c.H2
d.OH
Answer:
h2
Explanation:
mrs tuckers class is doing an experiment they fill up a cup with ice water they measure the temperature of both the water and the classroom after one hour . what will mrs tucker observe about the temperature of ice water after one hour
A. The temperature will increase
B. The temperature Will remain the same
C. The temperature will decrease greatly
D. The temperature Will decrease slightly
Answer:
Ofc D. bc if the temp decreases, that means it is getting colder u dummy! But if it increases, it is getting warmer.
Explanation:
I got it right on USATestprep for using common sense, mark me the brainliest.
If an acid has a pH of 2, what is its [H^ + ] ?
Show work
Check G the answer is up theree
In which phase of wound healing is fibrin most involved?
Answer:
Finally, coagulation occurs and reinforces the platelet plug with threads of fibrin which are like a molecular binding agent. The hemostasis stage of wound healing happens very quickly.
Explanation:
Hope it helps u
FOLLOW MY ACCOUNT PLS PLS
How do the equilibrium concentrations of the reactants compare to the equilibrium concentrations of the product?
Answer: It depends equilibrium constant K
Explanation: You need to to have reaction formula.
If K >> 1 then concentrations of products are much bigger than
concentrations of reactants. If K < < 1, concentration of products is small.
The following are reactants in the chemical reaction shown below.
6CO2 + 6H2O --> C6H12O6 + 6O2
A. CO2 and H2O
B. C6H12O6 and O2
C. H2O and O2
D. CO2 and C6H12O6
Answer:
A
Explanation:
Reactants are on the right side of the chemical reaction
All + HgCl, --------> AICI,
-AICI, + Hgl, balance equation then solve the problem
What mass, in grams, of All, is consumed when 138 grams of Hgl, is
produced? *
please help
Answer:
64.7g
Explanation:
The balanced chemical equation of this question is as follows;
AlI + HgCl2 → HgI + AlCl2
Based on the above equation, 1 mole of AlI (aluminum monoiodide) reacts to produce 1 mole of HgI (mercury iodide).
Using mole = mass/molar mass to convert mass of HgI to moles.
Molar mass of HgI = 200.59 + 127
= 327.59g/mol
Mole = 138/327.59
= 0.42mol
- If 1 mole of AlI (aluminum monoiodide) reacts to produce 1 mole of HgI (mercury iodide)
- Then 0.42 mol of HgI will be produced by 0.42mol of AlI.
Using mole = mass/molar mass
Mass = mole × molar mass
Molar mass of AlI = 27 + 127
= 154g/mol
Mass of AlI = 0.42 × 154
= 64.7g of AlI