Answer: The concentration of hydrogen ion is 2.5 x 10∧-3.
Explanation:
It is well known that; pH + pOH = 14
∴ pH + 11.40 = 14
pH = 14 -11.40 = 2.60
Remember that,
pH = - Log [ H+ ]
2.60 = - log [H+]
To get the hydrogen ion concentration, we take the anti-log of 2.60.
[H+] = Antilog 2.60 = 2.5 x 10∧-3.
A student weighs out a 6.64 g sample of , transfers it to a 500. mL volumetric flask, adds enough water to dissolve it and then adds water to the 500. mL tick mark. What is the molarity of cobalt(II) fluoride in the resulting solution
Answer:
the molarity of cobalt(II) fluoride in the resulting solution is = 0.137 M
Explanation:
Given that :
a student dissolves 6.64 g of CoF₂ into 500 mL of water
volume of the solution(water) = 500 mL = 0.50 L
The standard molar mass of CoF₂ is 96.93 g/mol
number of moles of CoF₂ = mass of CoF₂/molar mass of CoF₂
number of moles of CoF₂ = 6.64 g/96.93 g/mol
number of moles of CoF₂ = 0.0685 mol
The molarity of any given substance is known to be as the number of moles of solute dissolved in one litre of solution.
Thus ;
Molarity of cobalt(II) fluoride CoF₂ in the resulting solution is = number of moles / Volume in (L)
Molarity of cobalt(II) fluoride CoF₂ = 0.0685 mol/ 0.50 L
= 0.137 M
Thus ; the molarity of cobalt(II) fluoride in the resulting solution is = 0.137 M
A 75 lb (34 kg) boy falls out of a tree from a height of 10 ft (3 m). i. What is the kinetic energy of the boy when he hits the ground? Round your answer to the nearest joule. ii. What is the speed of the boy when he hits the ground? Round your answer to two significant figures. iii. Using the conversion factors of 1 m = 1.094 yd and 1 mi = 1760 yd, calculate the speed of the boy in miles per hour when he hits the ground.
Answer:
Kinetic energy of boy just before hitting the ground is [tex]\approx[/tex]1000 J.
Speed of boy just before hitting the ground is 7.67 m/s
or 17.16 mi/hr.
Explanation:
Given that:
Mass of boy = 75lb = 34 kg
Height, h = 10ft = 3m
To find:
Kinetic energy of boy when he hits the ground.
As per law of conservation of energy The potential energy gets converted to kinetic energy.
[tex]\therefore[/tex] Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'
The formula for potential energy is given as:
[tex]PE = mgh[/tex]
Where m is the mass
g is the acceleration due to gravity, g = 9.8 [tex]m/s^2[/tex]
h is the height of object
Putting all the values:
PE = [tex]34 \times 9.8 \times 3 \approx 1000\ J[/tex]
Hence, Kinetic energy is [tex]\approx[/tex]1000 J.
Formula for Kinetic energy is:
[tex]KE = \dfrac{1}{2}mv^2[/tex]
where m is the mass and
v is the speed
Putting the values and finding v:
[tex]1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s[/tex]
Given that:
1 m = 1.094 yd and 1 mi = 1760 yd
[tex]\Rightarrow 1609\ m = 1\ mi[/tex]
Converting 7.67 m/s to miles/hour:
[tex]\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h[/tex]
Phloem contains specialized cells that move sugars and other nutrients both
up and down in plants. Which object is the best model of one of these cells?
A. Water balloon
Answer:Drinking straw
Explanation: my quiz said so
The object that represents the best model of one of the phloem cells is the drinking straw.
What is Phloem?Phloem may be defined as a type of vascular tissue in plants that significantly conducts the passage of sugars and other metabolic products from the leaves to the roots. This mediates the migration of sugar which is synthesized in the leaves during photosynthesis.
Apart from this, the phloem also regulates the movement of nutrients from the roots to the upper part of the body. This function of phloem cells shares homology with the object known as a drinking straw that mediates the transport of any fluid in both directions.
Therefore, a drinking straw is an object that represents the best model of one of the phloem cells.
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Your question seems incomplete. The most probable complete question is as follows:
Can openerWater balloonDrinking StrawKitchen strainerThe image is of the formation of a fault-block mountain.
Which of these most likely occurs to result in the
formation of these mountains?
O The crust is compressed
O The crust does not spread apart
The center block is forced upward.
The hanging walls from the two parallel faults slip down
Answer:
d.
Explanation:
The Formation of these mountains will be caused by
The crust does not spread apartThe center block is forced upward.The hanging walls from the two parallel faults slip downOptions B, C, and D is correct.
What are mountains?Generally, a mountain is simply defined as a body that rises dramatically above its surroundings and is distinguished by steep slopes.
In conclusion, Mountains are formed from the formation of rocks over years in an Environment.
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c. Write a complete ionic equation for the reaction and identify the spectator ions.
The required complete ionic equation of the reaction
Pb(NO3)2+2KI---->PbI2+2KNO3 is Pb2+(aq) + 2 I−(aq) → PbI2(s)
What is ionic equation?A chemical equation in which the electrolytes in aqueous solution are expressed as dissociated ions.
Spectator ions in above equation are as follows- K +and NO3−
Define spectator ions.
Ions that are not involved in the actual chemical reaction are called spectator ions.
Net ionic equation of given reaction isPb⁺²+2I ⁻¹⟶PbI₂It shows only the ions which involves in the chemical reaction.
Therefore, K⁺ and NO3⁻ are spectator ions.
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why am i blonde.............
Answer:
because your parents carry the recessice gene or they are blond
Explanation:
it could also be ffrom a mutation or just because you dyed your hair
What is chemical potential energy?
Answer:
Chemical potential energy is the energy stored in the chemical bonds of a substance.
Explanation:
Two oxide of sulphur,A and B were analyzed and the results obtained showed that in oxide A,3.50g of sulphur combined with 6.00g of oxygen and in oxide B,2.80g of sulphur combined with 9.55g.Show that this result illustrate the law of multiple proportion
Answer:
See Explanaton
Explanation:
The law of multiple proportions states that when two same elements form more than a compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.
Oxide A
3.50g of sulphur combined with 6.00g of oxygen
Oxygen:Sulphur = 6 : 3.5
Oxide B
2.80g of sulphur combined with 9.55g
Oxygen : Sulphur = 9.55 : 2.8
Therefore:
The ratio of Oxygen to Sulphur in Oxides A and B is:
[tex]\dfrac{\text{Oxygen}}{\text{Sulphur}} \implies \dfrac{6}{3.5}:\dfrac{9.55}{2.8} = \dfrac{1.7}{1}:\dfrac{3.4}{1}=1:2[/tex]
Ratio of Oxygen=1:2
There is exactly twice in Oxide B as in Oxide A.
This result illustrates the law of multiple proportions.
Identify the correct statement regarding the strength of chemical bonds.
Weak bonds require more surface area to form than strong bonds.
A weak bond forms from a smaller change in energy compared to a strong bond.
Strong bonds occur with high temperature and weak bonds with low temperature.
Weak bonds require more heat to form than strong bonds.
Answer:
B.
Explanation:
A weak bond forms from a smaller change in energy compared to a strong bond.
En la electrólisis del Cloruro de plomo se han depositado 2.6 gramos del metal en 20 minutos el peso atómico del plomo es 206 calculo la intensidad de la corriente eléctrica empleada AYUDENNNNN PLISSSS es para hoy!!!!!
Answer:
2.01 A
Explanation:
Para esta pregunta debemos empezar por la semi-reaccion del plomo:
[tex]Pb^+^2~_(_a_q_)~+~2e^-~->~Pb_(_s_)[/tex]
Se intercambian dos electrones en la semi-reacción del plomo. Si tenemos en cuenta la ecuación:
[tex]n=\frac{I*t}{z*F}[/tex]
Donde:
n= Moles depositados
I= Intensidad de corriente (en Amperios)
z= Numero de electrones intercambiados
F= Constante de faraday = 96484 C/mol
t=tiempo (en segundos)
Que conocemos de esta ecuación?
Los moles (se pueden calcular a partir de la masa atómica del plomo, 207.2 g/mol)
[tex]2.6~g~Pb\frac{1~mol~Pb}{207.2~g~Pb}=0.0125~mol~Pb[/tex]
El tiempo (hay que convertirlo a segundos):
[tex]20~min\frac{60~s}{1~min}=1200~s[/tex]
Z (Numero de electrones)
De acuerdo a la semi-reacción son intercambiados 2 electrones.
Por lo tanto podemos resolver para "I":
[tex]I=\frac{n*z*F}{t}=\frac{0.0125~mol*2*96484\frac{C}{mol}}{1200~s}[/tex]
[tex]I~=~2.01~\frac{C}{s}=2.01~A[/tex]
Espero que sea de ayuda!
Polarity of water. Which is the correct answer?
After 273 m3 of ethylene oxide at 748 kPa and 525 K is cooled to 293 K, it is allowed to expand to 1100. m3. The new pressure is _____kPa
Answer:
[tex]\large \boxed{\text{104 kPa}}[/tex]
Explanation:
To solve this problem, we can use the Combined Gas Laws:
[tex]\dfrac{p_{1}V_{1} }{n_{1}T_{1}} = \dfrac{p_{2}V_{2} }{n_{2}T_{2}}[/tex]
Data:
p₁ = 748 kPa; V₁ = 273 m³; n₁ = n₁; T₁ = 525 K
p₂ = ?; V₂ = 1100. m³; n₂ = n₁; T₂ = 293 K
Calculations:
[tex]\begin{array}{rcl}\dfrac{p_{1}V_{1}}{n_{1} T_{1}} & = & \dfrac{p_{2}V_{2}}{n_{2} T_{2}}\\\\\dfrac{\text{748 kPa}\times \text{273 m}^{3}}{n _{1}\times \text{525 K}} & = &\dfrac{p_{2}\times \text{1100. m}^{3}}{n _{1}\times \text{293 K}}\\\\\text{390.0 kPa} & = &3.754{p_{2}}\\p_{2} & = & \dfrac{\text{390.0 kPa}}{3.754}\\\\ & = & \textbf{104 kPa} \\\end{array}\\\text{The new pressure is $\large \boxed{\textbf{104 kPa}}$}[/tex]
what is Lfusion in the equation Q=mLfusion
Answer:
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
Explanation:
Latent heat is basically termed as hidden heat. It is defined as the amount of heat required to change 1 g of a substance at the temperature of its melting point from the solid to the liquid state at constant temperature.The formula that relates heat and latent heat of fusion is given by :[tex]Q=mL_{\text{fusion}}[/tex]
Here,
m is mass of substance
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
heterogeneous non example
Heterogeneous 'mixtures' (because they don't meet the definition of mixtures) are mixtures substances that aren't completely uniformly spread out. They haven't reacted with the solvent to become a solution.
Explanation: There are 2 types of heterogeneous solutions, A Colloid and a suspension.
Colloid: You can check if a mixture is heterogeneous by passing a light ray through it. This may cause the Tyndall effect (If the mixture is a colloid) when the Colloidal Heterogeneous mixture's particles are so small that they refract the beam of light and the path of light will be visible, like if you add 3 drops of milk in a glass of Water and shine a laser light through it. This is because the particles are too small to be seen by the unaided eye but big enough to scatter you laser light. However that particles won't settle down or will be separated by a filter paper due to particles' small size.
Suspension: A solution will be a solution when the particles of the Mixture is big enough to be seen by the unaided eye. Like if you mix sand and Water, the sand will eventually settle down due to Gravity. The mixture's solute will be big enough to pass through a filter paper.
What is equilibrium?? Give examples
Answer:
it is when a state in which opposing forces or influences are balanced.
A example of equilibrium is in economics supply and demand are equal.
Explanation:
Answer:
Compromise of 1850
Explanation:
Why does carbon form covalent bonds?
Answer:
Carbon has 4 electrons in its outermost shell. ... Therefore, carbon completes its octet by sharing its 4 electrons with other carbon atoms or with atoms of other elements and forms covalent bond. It forms strong covalent bonds because of its small size.
Explanation:
Which statement correctly describes a feature of the rock cycle?
PA
Rocks are preserved through the process.
Rocks change from one type to another.
Different rock groups are not related to one another.
Rocks change from one type to another in a specific order.
Answer:
It’s D
Explanation:
Answer:
D Rocks change from one type to another in a specific order.
Explanation:
What is the best definition of chemistry?
A. The study of mass, energy, and light
B. The study of life and energy
C. The study of experiments and theories
D. The study of matter, its properties, and its reactions
which of the following us not a property of salt in the ionic and covalent properties lab
Explanation:
I think Low melting point
because NaCl (salt has mp 801 degC)
Water has mp 0 degC
Which part of the electromagnetic spectrum is nearest to X-rays? microwaves infrared light gamma rays radio waves
Answer:
The correct answer to the following question will be Option A (Microwaves).
Explanation:
This tends to be a source of radiation, including some signals, infrared radiation, x-rays as well as gamma. This appears to have a diverse variety of uses, involving communications, radar, and scheduling, but best known by most individual people. Sections of society used handheld devices, including tablets, as well as WiFi.The other given choices are not related to the given circumstances. So that option A seems to be the appropriate one.
Answer:
its a
Explanation:
Calculate the payback time if she insulates the loft with 300 mm insulation when: area of loft space = 100m^2 cost of roll of 100 mm thick loft insulation that covers 8.3m^2 = £20 cost of putting the insulation into the loft = £120 savings per year = £80 per 100 mm Payback Time = installation cost divided by annual savings
Answer: Payback time = 0.0075
Explanation: Since payback time is calculated as:
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
First determine the installation cost:
100 mm thick insulation covers 8.3 m². Then 300 mm covers 24.9 m².
To cover 8.3m² costs £20. Then, the cost to cover 24.9 m² is:
cost = [tex]\frac{20*24.9}{8.3}[/tex]
cost = £60
The cost of putting the insulation is £120, so the total cost is:
total cost = £60 + £120
total cost = £180
Savings per year per 100 mm thick is £80. For 300 mm, the value of annual savings is:
savings = [tex]\frac{300*80}{100}[/tex]
savings = 240
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
payback time = [tex]\frac{180}{240}[/tex]
payback time = 0.75
how many atoms are contained in 2.70g of aluminum provided that 32g of sulphur equals 6.02 × 10^(23)atoms
Answer:
[tex]1.63 \times {10}^{24} [/tex]
one atom of an element = 6.02 \times {10}^{23} atom
The mass of one atom of sulphur = 32g
The mass of one atom of aluminium = 27g
so one atom of aluminium = 6.02 \times {10}^{23}
27g of AL = 6.02 \times {10}^{23} atom
2.70g of AL = X atoms
Then you cross multiply ........
and get the answer
.
How many moles of silver are equivalent to 2.408 x 10^24 atoms
The mole is used to measure small particles like atoms and molecules. The 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.
Given here,
The number of atoms
[tex]\bold{2.408 x 10^2^4 }[/tex]
Number of moles = ?
1 mol of substance = [tex]\bold{ 6.02 x10^2^3}[/tex]
Hence,
moles of silver,
[tex]\bold {= \dfrac {2.408 x 10^2^4 } { 6.02 x10^2^3} }}\\\\\bold {= 4 mol}[/tex]
Therefore, the 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.
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Which is one way that a short-term environmental change will most likely affect organisms within an ecosystem? A)It will lead to larger populations. B)It will lead to speciation. C)It will lead to adaptation. D)It will lead to forced migration.
Answer:
D)It will lead to forced migration.
Explanation:
Forced migration is an involuntary, sudden movement of organisms from one geographical location to another. This is often in response to short term environmental changes such as drought, famine, etc
When an ecosystem suddenly comes under stress due to these short term environmental changes, organisms may not be left with any other choice but to move or go to new locations in the quest for survival. The organisms may not have left the ecosystem in the absence of such short term ecological stress. This is what is meant by forced migration.
Answer:
D forced migration
Explanation:
What biological sample do home pregnancy tests use to detect pregnancy?
Answer:
The biological sample that pregnancy tests use to detect pregnancy is urine
Answer:
yes
Explanation:
the urine in the the tester will find hormones to determine if pregnant or not
a heating fan is supplied with 150 j of electricity which is nonverts to 113 j of thermal energy and 37 j of sound energy
How efficient is the heating fan?
Answer:
Heating Fan is 75.33% efficient.
Explanation:
As it is mentioned that the given fan is a HEATING FAN, it means the it is used for provided heat (thermal energy) to the surrounding. Hence, its efficiency depends upon how much heat/thermal energy is provides.
We can state that.
Total Energy provided = 150 J
Useful Energy = 113 J
Wasted Energy = 37 J
The efficiency of the heating fan can be given by following formula:
Efficiency = ( Useful Energy / Total Energy ) × 100
Efficiency = ( 113 J / 150 J) × 100
Efficiency = (0.7533)× 100
Efficiency = 75.33%
Which is a negative effect of deforestation on the environment? habitat restoration, desertification, soil production, or urbanization
Answer:
The correct option is desertification
Explanation:
Deforestation is the deliberate act of pulling down trees to provide a clear land for space or to make use of the trees for other purposes such as grazing, farming, timber fire wood, building and constructions, urban utilization, access roads, expansion, development of infrastructures, grazing of cattle and mining
The effects of deforestation includes climate change, flooding, increase in the proportion of green house gases in the atmosphere, soil erosion and desertification.
A negative effect of deforestation is desertification.
Deforestation refers to the cutting down of trees. There are many reasons why people may cut down trees. One of the popular reasons why people cut down trees is to obtain timber which is used for construction and as fuel.
An important consequence of the felling of trees also called deforestation is that a once fertile land may gradually be turned into a desert area. This is known as desertification.
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what is the molar mass of magnesium tartrate
Answer:
172.385 g/mol
Explanation:
Magnesium Tartrate is C4H4MgO6
C - 12.01 g/mol
H - 1.01 g/mol
Mg - 24.305 g/mol
O - 16.00 g/mol
12.01(4) + 1.01(4) + 24.305 + 16(6) = 172.385 g/mol
Answer:
172.38
Explanation:
[tex]C_4H_4MgO_6\\C=12.01\\H=1.01\\Mg=24.30\\O=16.00\\\\4(12.01)+4(1.01)+24.30+6(16.00)\\48.04+4.04+24.30+96\\=172.38[/tex]
C = 12.01
H=1.01
Mg=24.30
O =16.00
4(12.01)+4(1.01)+24.30+6(16.00)
48.04 +4.04+24.30+96
=172.38
For each of the compounds, find the length of the longest carbon chain in the box provided.
CH,
CH3 -CH2-CH2-CH2-CH-CH2-CH2 - CH2 - CH3
CH,CH,CH,
HC
CH-CH2-CH3
CH,CH.CHCCH,CH,CH,
1
CH2
H.C CH.CH
CH3
<
Answer:
In First compound the longest chain contains 7 C atoms.
In the Second compound the longest chain contains 9 C atoms.
In the Third compound the longest chin contains 7C atoms.
Explanation:
In first compound the longest chain contains 7 carbon atoms.In the second compound the longest chain contains 9 carbon atoms.In the third compound the longest chin contains 7 carbon atoms.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Which example is a long-term environmental change? La Niña El Niño climate change small asteroid impact
The correct answer is C. Climate change
Explanation:
Long-term environmental changes occur as major events affect the environment and ecosystems indefinitely. These events differ from short-term environmental changes because the effect of short-term environmental changes is mainly temporary. Also, long-term changes are usually gradual.
Climate change is an example of long-term environmental changes because this implies indefinite and major changes in weather patterns and ecosystems. For example, it is believed climate change will decrease the amount of ice in Earth, change sea level, and lead to the extinction of dozens of species. This does not occur with events such as el niño or a small asteroid impact that affect the environment for a short time and do not imply major changes.
Answer:
it is c) climate change
Explanation:
i just took the quiz
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