Answer:
yes, coal for example produces energy by burning but there are several alternatives such as water or solar which are 2 growing energy sources.
Explanation:
hope this helps!
Which of the following are common characteristics of nuclei of the same element?
Answer:
D
Explanation:
the Same number of proton
Which two substances combine in a car's engine to provide energy?
Answer:
Fuel and oxygen
Explanation: Carbon in the fuel and the oxygen from the air burns.
the current in the first circuit is 0.4 A. A second identical bulb is added in series. What will the current in the second circuit be?
pls answer quickly as possible i have an examination tomorrow so I am preparing for the tests
thanks
The current in the second circuit in series with the first circuit is 0.4 A.
Current in series circuit
The current flowing in series circuit is the same across all the component of the circuit.
The total voltage drop in a series circuit is given as;
V = IR₁ + IR₂ + IR₃
V = I(R₁ + R₂ + R₃)
If the current in first circuit is 0.4 A, when second identical bulb is added in series, the current in the second circuit will be 0.4 A.
Thus, the current in the second circuit in series with the first circuit is 0.4 A.
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A compound is known to have a molar mass of 391.5 g/mol. Find the molecular formula of the compound, given the results of an analysis of a 310.8-g sample that revealed that the sample contains only boron and iodine. The mass of the iodine in the sample is found to be 302.2 g
Going by the result of the analysis as stated in the illustration, the molecular formula of the compound will be [tex]BI_3[/tex]
Molecular formulaMolecular formula = n[empirical formula]
Where n = molar mass/empirical mass
Empirical formula
B = 8.6/10.8
= 0.8
I = 302.2/126.9
= 2.38
Dividing by the smallest:
B = 0.8/0.8 = 1
I = 2.38/0.8 = 3
Empirical formula = [tex]BI_3[/tex]
Empirical formula mass = 10.811 + 126.9x3
= 391.5
n = 391.5/391.5 = 1
Thus, the molecular formula of the compound = empirical formula = [tex]BI_3[/tex]
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gas occupies 100.0 mL at a pressure of 780 mm Hg. What is the volume of the gas
when its pressure is increased to 880 mm Hg?
Answer:
Final volume after applying 880 mmHg pressure = 89.28
Explanation:
Initial volume (V 1)= 100 ml
Initial pressure (P1) =780 mm Hg = 780/780 = 1atm
Final pressure (P2)=880 mm Hg = 880/780 =1.12 atm
Final volume (V2)=?
We know that,
Applying Boyle's law,
P1 V1=P2 V2
1*100=1.12*V2
100=1.12*V2
100/1.12=V2
89.28=V2
V2=89.28 ml
Hope this helps you. Please mark me as a brainlist.
2. What are two types of local winds?
Answer:
The two main types of local winds are:
1. Sea Breezes.
2. Land Breezes.
Answer:
Out of all the local winds, two of the main local wind types will be land breezes and sea breezes. Or katabatic and foehn winds, and Anabatic winds.
hope this helps
According to the periodic table how many elements are metal
Barium fluoride (BaF2) has a Ksp = 2. 5 × 10–5 (mol/L)3.
i. Write the dissolution reaction of BaF2, including all states. (0. 5 points)
ii. Write the expression for Ksp for BaF2. (0. 5 points)
iii. Write the Ksp expression as an algebraic equation, using the variable x to represent concentrations. (1 point)
iv. Find the solubility of BaF2 by solving the equation you wrote in part iii. (0. 5 points)
This problem is asking for the dissolution reaction of barium fluoride, both the equilibrium and Ksp expressions in terms of concentrations and x and its molar solubility in water. Thus, answers shown below:
[tex]BaF_2(s)\rightleftharpoons Ba^{2+}(aq)+2F^-(aq)[/tex][tex]Ksp=[Ba^{2+}][F^-]^2[/tex][tex]Ksp=(x)(2x)^2[/tex]0.0184 M.Solubility productIn chemistry, when a solid is dissolved in water, one must take into account the fact that not necessarily its 100 % will be able to break into ions and thus undergo dissolution.
In such a way, and specially for sparingly soluble solids, one ought to write the dissolution reaction at equilibrium as shown below for the given barium fluoride:
[tex]BaF_2(s)\rightleftharpoons Ba^{2+}(aq)+2F^-(aq)[/tex]
Next, we can write its equilibrium expression according to the law of mass action, which also demands us to omit any solid and refer it to the solubility product constant (Ksp):
[tex]Ksp=[Ba^{2+}][F^-]^2[/tex]
Afterwards, one can insert the reaction extent, x, as it stands for the molar solubility of this solid in water, taking into account the coefficients balancing the reaction:
[tex]Ksp=(x)(2x)^2[/tex]
Finally, we solve for the x as the molar solubility of barium fluoride as shown below:
[tex]2.5x10^{-5}=(x)(2x)^2\\\\2.5x10^{-5}=4x^3\\\\x=\sqrt[3]{\frac{2.5x10^{-5}}{4} } \\\\x=0.0184M[/tex]
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A solid has a very high melting point, great hardness, and poor electrical conduction. This is a(n) ________ solid
If 2H2SO4 is part of a chemical equation, how many oxygens atoms from sulfuric acid are involved in the chemical equation
Answer: 8
Explanation: k*4O=2*4O=8O
What is the pH of a KOH solution that has [H ] = 1. 87 × 10–13 M? What is the pOH of a KOH solution that has [OH− ] = 5. 81 × 10−3 M? What is the pH of a solution of NaCl that has [H ] = 1. 00 × 10–7 M?.
pH is the hydrogen ion concentration and pOH is the hydroxide ion concentration in the solution. pH KOH is 12.73, pOH KOH is 2.24 and pH NaCl is 7.
What are pH and pOH?pH is the negative log of the hydrogen ion concentration and pOH is the negative log of the hydroxide ion concentration.
The relation between the pH and pOH can be given as, [tex]\rm pOH = 14 - pH[/tex]
The pH of KOH can be calculated by the formula,
[tex]\rm pH = \rm -log [H^{+}][/tex]
In the first case, the concentration of the KOH is [tex]1. 87 \times 10^{-13}\;\rm M[/tex]
Substituting values in the equation:
[tex]\begin{aligned} \rm pH &= \rm -log [H^{+}]\\\\&= \rm -log [1. 87 \times 10^{-13}\;\rm M ]\\\\&= 12.73\end{aligned}[/tex]
Hence, the pH of KOH is 12.73.
pOH of KOH can be calculated by the formula,
[tex]\rm pOH = \rm -log [OH^{-}][/tex]
The hydroxide concentration of the KOH solution is [tex]5. 81 \times 10^{-3}\;\rm M[/tex]
Substituting value in the equation:
[tex]\begin{aligned} \rm pOH &= \rm -log [OH^{-}]\\\\&= \rm -log [5. 81 \times 10^{-3}\;\rm M ]\\\\&= 2.24 \end{aligned}[/tex]
Hence, the pOH of KOH is 2.24
The pH of NaCl can be calculated by the formula,
[tex]\rm pH = \rm -log [H^{+}][/tex]
In the third case, the concentration of the NaCl is [tex]1. 00\times 10^{-7}\;\rm M[/tex]
Substituting values in the equation:
[tex]\begin{aligned} \rm pH &= \rm -log [H^{+}]\\\\&= \rm -log [1. 00 \times 10^{-7}\;\rm M ]\\\\&= 7 \end{aligned}[/tex]
Hence, the pH of KOH is 7.0.
Therefore, KOH is basic and NaCl is approximately neutral.
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I got more(science)please help I’m to lazy-
Answer:
D :DDDDDDDDDDD
How much in grams, does 5.68 x 1022 formula units of potassium dichromate weigh?
Answer:
Explanation:
The molecular formula for Potassium Dichromate is K2Cr2O7. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Potassium Dichromate, or 294.1846 grams.
Note that rounding errors may occur, so always check the results.
Rainforests are not generally considered a source of _______.
a.
foods
b.
spices
c.
medicines
d.
none of the above
Please select the best answer from the choices provided
A
B
C
D
Rainforests are not generally considered a source of none of the above choices. You can get food from Rainforests, and also spices and medicines. In fact, Rainforests have a variety of plants that have medicinal properties. When you know how to find the right plant in the rainforests, you can access almost everything.
Hence, your answer is D. None of the above-------------------------------------------------------------------------------------------------------------
Thanks!
Answered by: FieryAnswererGT
#learnwithbrainly
Answer:
D. None of the above
Explanation:
trusttt
Identify the different stages of the water cycle and the changes in the phases of water. Illustrate the arrangement and motion of particles in each phase change. Use the water cycle diagram below as reference.
The water cycle is largely composed of evaporation, condensation and precipitation.
What is the water cycle?The water cycle has to do with the movement of water throughout the ecosystem. It is one of the biogeochemical cycles that exists in nature. In the water cycle, water evaporates from the earth surface, condenses and falls as rain.
Hence, the major components of the water cycle are;
EvaporationCondensationPrecipitationLearn more about water cycle: https://brainly.com/question/1151425
Calculate the ratio of H ions to OH– ions at a pH = 7. Find the concentration of H ions to OH– ions listed in Table B of your Student Guide. Then divide the H concentration by the OH– concentration. Record this calculated ratio in Table A of your Student Guide. Compare your approximated and calculated ratios of H ions to OH– ions at a pH = 7. Are they the same? Why or why not? Record your comparison in Table A. What is the concentration of H ions at a pH = 7? mol/L What is the concentration of OH– ions at a pH = 7? mol/L What is the ratio of H ions to OH– ions at a pH = 7? :1.
The pH can be defined as the measure of the acidity or the basicity of the solution. The ratio of hydrogen ion concentration and hydroxide ion concentration at pH 7 is 1.
What is hydrogen ion concentration?The hydrogen ion concentration can be given as the amount of hydrogen percent in the sample solution.
The pH has been the negative logarithmic value measurement of the hydrogen ion in the sample. The sum of the hydrogen ion and the hydroxide ion in the sample has been a constant 14.
[tex]\rm pH+pOH=14[/tex]
The pH can be given as:
[tex]\rm pH=-log[H^+][/tex]
At pH 7 neutral pH the concentration of Hydrogen ion and hydroxide are equal i.e.
[tex]\rm 7=-log[H^+]\\H^+=10^{-7}\;M[/tex]
The hydroxide ion concentration has been given as:
[tex]\rm pOH=-log[OH^-]\\7=-log[OH^-]\\OH^-=10^{-7}\;M[/tex]
The concentration of hydrogen and hydroxide are equal at pH 7. Thus, the ratio of the concentration has been 1.
This states the sample to be neutral.
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True or false, some molecules have the same molecular formula as their empirical formula.
Answer:
True, some molecules have the same molecular formula as their empirical formula.
Explanation:
The empirical formula of many compounds may be the same. Formaldehyde, for example, has the chemical formula CH2O, which is equal to the empirical formula of glucose. Each molecule of formaldehyde has one carbon atom, two hydrogen atoms, and one oxygen atom.
Is the production of nitrogen(II) oxide exothermic or endothermic?
what is the term called when it means to lacks properties of metal?
Answer:
The used term is nonmetal.
Explanation:
Nonmetals are elements that are not shiny or are not good conductors of electricity or heat.
The periodic table has approximately 23 nonmetals in it.
In the periodic table, we can find elements. These ones could be nonmetal and metals.
The elements that lack metallic properties are the nonmetals.
Metals are good conductors of heat and electricity, like Cu or Fe.
Although, nonmetals are not good conductors.
Hello I'm always here to help!!!
___________________________
A nonmetal is an element that lacks the majority of metal's characteristics. Nonmetals make up all of the elements in the shaded boxes. On Earth, many of the nonmetals are common elements. Nonmetals have physical traits that are diametrically opposed to metals. Solid nonmetals are dull, which means they aren't gleaming.
___________________________
Have a great day!!!!
What is the solid that forms when a solution starts to freeze.
* I NEED THIS *
Which of the following statements about oceans is incorrect?
A: Oceans collect water from other reservoirs including streams and rivers.
B: Oceans are the main source of drinking water on Earth's surface.
C: Oceans are connected to other reservoirs through evaporation and precipitation.
D: Oceans are the main type of reservoir that contain salt water.
Answer:
B is incorrect
Explanation:
Ocean are made of salt water which is undrinkable therefore they are not any type of drinking water source.
Mass to molecules? 12.5 g N2 to mole?
Answer:
0.44621502566628746
Explanation:
A gas initially at 273k is heated such that it volume and pressure became twice their original volume what is the new temperature of the gas
Answer:
1092K
Explanation:
We can use the combined gas law to answer this question:
P1V1/T1 = P2V2/T2,
where P, V and T are the Pressure, Volume, and Temperature for initial (1) and Final (2) conditions. Temperatures must be in Kelvin.
The problem states that V2 = 2V1 and P2 = 2P1.
Let's rearrange to solve for T2, which is the question:
T2 = T1(P2/P1)(V2/V1)
Note how the pressure and temperature values are written: as ratios. Enter the values:
T2 = (273K)(P2/P1)(V2/V1)
T2 = (273K)(2P1/P1)(2V1/V1) [Use the expressions for V2 and P2 from above]
T2 = (273K)(2)(2)
T2 = 1092K
Which symptoms are common with cardiac dysrhythmias? Select all that apply.
low blood pressure
fluid buildup in the hands
dizziness
palpitations
headaches
Answer: low blood, dizziness, and palpitations
Explanation: Im doing the assignment now
2 Upper P Upper O Upper C l Subscript 3 Baseline (g) + heat double-headed arrow 2 Upper P Upper C l Subscript 3 Baseline (g) + Upper O Subscript 2 Baseline (g) For the equilibrium system described by this equation, what happens if the temperature is decreased?
Answer:
The equilibrium will shift left.
Explanation:
Hope this helps <3
Answer:
1. left 2.right
Explanation:
edge!
Why is glass useful for making eyeglasses
Answer:
because it's the glass that goes on eyeglasses
Answer:
Because it is transparent
three ways in which atmosphere nitrogen can be fixed
There are three major ways in which this happens: first, by lightning, when the energy of lightning strikes breaks apart the N2 bonds; second, by industrial methods, when humans break the bonds with high pressure and temperatures, and hydrogen; finally, by biological fixation, with bacteria living in the soil.
4. How many moles of KBr are found in 3 Liters of 0.4 M solution?
A.7.1moles
B. 43.9moles
C. 2.6moles
D 1.2 moles
There are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
HOW TO CALCULATE NUMBER OF MOLES?The number of moles of a substance can be calculated by multiplying the molarity by the volume.
No. of moles = Molarity × volume
According to this question, 3L of a KBr solution are contained in a 0.4M.
no. of moles = 3L × 0.4M = 1.2moles
Therefore, there are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
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What is the pH of a solution of RbOH with a concentration of 0.86 M? Answer to 2 decimal places
Answer:The pH of the solution is given by pH=−log([H3O+])
Explanation:so you can't use
pH
=
−
log
(
0.150
)
because that's the concentration of the hydroxide anions,
OH
−
, not of the hydronium cations,
H
3
O
+
. In essence, you calculated the
pOH
of the solution, not its
pH
.
Sodium hydroxide is a strong base, which means that it dissociates completely in aqueous solution to produce hydroxide anions in a
1
:
1
mole ratio.
NaOH
(
a
q
)
→
Na
+
(
a
q
)
+
OH
−
(
a
q
)
So your solution has
[
OH
−
]
=
[
NaOH
]
=
0.150 M
Now, the
pOH
of the solution can be calculated by using
pOH
=
−
log
(
[
OH
−
]
)
−−−−−−−−−−−−−−−−−−−−
In your case, you have
pOH
=
−
log
(
0.150
)
=
0.824
Now, an aqueous solution at
25
∘
C
has
pH + pOH
=
14
−−−−−−−−−−−−−−so you can't use
pH
=
−
log
(
0.150
)
because that's the concentration of the hydroxide anions,
OH
−
, not of the hydronium cations,
H
3
O
+
. In essence, you calculated the
pOH
of the solution, not its
pH
.
Sodium hydroxide is a strong base, which means that it dissociates completely in aqueous solution to produce hydroxide anions in a
1
:
1
mole ratio.
NaOH
(
a
q
)
→
Na
+
(
a
q
)
+
OH
−
(
a
q
)
So your solution has
[
OH
−
]
=
[
NaOH
]
=
0.150 M
Now, the
pOH
of the solution can be calculated by using
pOH
=
−
log
(
[
OH
−
]
)
−−−−−−−−−−−−−−−−−−−−
In your case, you have
pOH
=
−
log
(
0.150
)
=
0.824
Now, an aqueous solution at
25
∘
C
has
pH + pOH
=
14
−−−−−−−−−−−−−−
If 25 ml of KBr is dissolved in 100 ml of water, what is the percent volume of the solution produced?
Answer:
4
Explanation:
You need divide 100/25 and that's it
