Answer:
[tex]2.71(10^{25})[/tex] molecules
Explanation:
Remember 1 mol is equal to Avogadro's number
[tex]45 mol (\frac{6.02(10^{23}) molecules}{1 mol})[/tex]
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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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
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
mass is 89.6 grams (g), and its volume is 10 cubic centimeters (cm3). What’s the density of the sample?
Explanation:
density = mass/volume
density = 89.6/10
density = 8.96g/cm³
do you always have to begin with two compounds in a neutralization reaction
Answer:
Yes.
Explanation:
Only an acidic compound and then a basic compound react(neutralization reaction) to give a salt.
Acid+Base=Salt+Water.
Hope this helps❤❤❤
Yes, we always have to begin with two compounds in a neutralization reaction.
What is a neutralization reaction?A neutralization reaction can be defined as a chemical reaction in which an acid and base quantitatively react together to form salt and water as products.
When an acid and a base react, the reaction is called a neutralization reaction. That's because the reaction produces neutral products. Water is always one product, and salt is also produced. Salt is a neutral ionic compound.
Yes, we always have to begin with two compounds in a neutralization reaction.
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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.
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]
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
sea water boiling below 100 degrees celsius true or false
Answer:
Explanation:
its true
hope this helps
plz mark as brainliest!!!!!
Answer:
True
Explanation:
Which question would most likely be studied by a physicist?
A. Were there ever any living organisms on Mars?
B. How can the forces on a space probe be controlled so it will land
on Mars?
O C. What type of substances make up the soil on Mars?
O D. Should the government spend taxpayers' money to send space
probes to Mars?
Answer:A
Explanation: Were there any living organisms is the answer because physics is the study of matter,its motion and behaviour of space and time and some other topics like energy and force.
Answer:
B
Explanation:
Forces and vectors on a probe are a physics thing
Which is one way that analyzing ice benefits scientists who study ancient climates? Scientists can analyze frozen volcanic dust to help predict eruptions. Scientists can drill deep into the ice to collect ice cores. Scientists can use pollen grains in ice to make inferences about the climate area. Scientists can study tree rings in ice to learn more about past climates.
Answer:
The correct option is;
Scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases
Explanation:
The study of past climates also known as paleoclimatology, is accomplished by acquiring information from proxy data sources which are physical environment characteristics that are preserved through time to remake the conditions of past climate
Past physical environmental characteristics, from which information about ancient climate can be gained are stored in nature's climate variability records including, ice cores, rings in tree stems, fossil pollen, sediments found in the waters of the ocean
The proxy sources provide a means of understanding the conditions of ancient climate before advent of climate measurement.
Therefore, one way that analyzing ice benefits scientists who study ancient climates is that scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases from past climates.
Answer: B: Scientists can study the layers of ice cores to gather information about past atmospheric composition.
Explanation: Got it right on a test!
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.
Which of the following is the best definition of a physical change?
A. Something that can be observed or measured while changing the identity of the substance.
B. A nail rusting.
C. A change that occurs without changing the identity of the substance.
D. Ice melting into water.
Answer:
the answer is D.ice melting into water
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 strainerWhat 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
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:
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.
The ____ cycle is not a nutrient cycle
Answer:
Water cycle
Explanation:
The water cycle, also called as the hydrologic cycle that describes the continual flow of water i.e on over and beyond the surface of the Earth.
The nutrient cycle refers to the cycle in which there is a movement and exchange of organic and inorganic matter
Therefore the water cycle is not a nutrient cycle and hence the same is to be considered
Answer:
water cycle
Explanation:
:)
Balance the chemical equations
Answer:
Explanation:
1). Ca(NO₃)₂ + KI → CaI + K(NO₃)₂
This equation is incorrect.
When Ca⁺⁺ reacts with I⁻, final product is CaI₂
And when K⁺ react with NO₃⁻, final product is KNO₃
Hence the equation will be,
Ca(NO₃)₂ + KI → CaI₂ + KNO₃
Now we have to balance this equation.
Ca(NO₃)₂ + 2KI → CaI₂ + KNO₃
↓
Ca(NO₃)₂ + 2KI → CaI₂ + 2KNO₃
2). Ca(NO₃)₂ + KOH → CaOH + K(NO₃)₂
This equation is incorrect,
Since the reaction of Ca⁺⁺ with OH⁻ gives the final product Ca(OH)₂
And final product of K⁺ and NO₃⁻ is KNO₃
Therefore, the equation will be,
Ca(NO₃)₂ + KOH → Ca(OH)₂ + KNO₃
Now we will balance this equation by changing the coefficients of the molecules until the number of atoms on both the sides become equal.
Ca(NO₃)₂ + KOH → Ca(OH)₂ + 2KNO₃
↓
Ca(NO₃)₂ + 2KOH → Ca(OH)₂ + 2KNO₃
3). Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2Na(NO₃)₂
This equation is incorrect,
Since the reaction of Na⁺ and NO₃⁻ gives the final product NaNO₃.
Therefore, the correct equation will be,
Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2NaNO₃
This equation is in the balanced form.
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 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:
Which title is most appropriate for this table? ANSWERS: Uses of Functional Groups Involving Oxygen Natural Sources of Functional Groups Involving Oxygen Uses of Functional Groups Involving Halides and Amines Natural Sources of Functional Groups Involving Halides and Amines
Answer:
Uses of Functional Groups Involving Oxygen
Explanation:
From the table given above, we obtained the following:
1. The functional group of each compound contains oxygen.
2. The table shows the uses of each compound.
From the observations made above, we can say that the most appropriate title for the table is:
Uses of Functional Groups Involving Oxygen.
Answer:
A.Explanation:
first guy is right give him brainliest
mention gay-lussac's law of combining volumes
Answer:
When volume is kept constant (kept the same), Gay-Lussac's law states that the pressure of gas varies directly with the temperature of the gas. The equation would be [tex]\frac{P1}{T1}=\frac{P2}{T2}[/tex], Where P is the pressure (in atm) and T is the temperature (in K°).
Explanation:
Answer:
When volume is kept constant (kept the same), Gay-Lussac's law states that the pressure of gas varies directly with the temperature of the gas. The equation would be , Where P is the pressure (in atm) and T is the temperature (in K°).
Explanation:
What can you infer about the results of numerical models in 1966 for polar caps
made of water ice?
Answer:
Those people could sustain on Mars, by living closer to the poles
Explanation:
As it is given that caps involve the water ice instead of the carbon dioxide
And, current observations of spectrum analyzed that the polar caps are totally different from one other i.e northern one involves more water ice while on the other hand, the southern one involves most of the carbon dioxide
Moreover, the astronomers unable to see to spectrum portions as the atmosphere absorbs the wavelength
So we conclude that the people could survive on mars if they live near to poles
Tick the correct choice and give reason why you have selected the particular choice. [20] 1. A cup of hot tea is left in the same room as a bowl of ice-cream. What is likely to happen to both after some time, if both are placed on the dining table? A. The tea becomes as cold as ice cream B. The ice cream becomes warmer than the tea C. The tea cools to room temperature, the ice cream melts and warms to room temperature D. The tea becomes colder than before but not as cool as the air in the room
Answer:
C. The tea cools to room temperature, the ice cream melts and warms to room temperature.
Explanation:
The tea's temperature was higher than room temperature. The ice cream's temperature was lower than room temperature. After some time, both items will become room temperature, which results in cooling and melting.
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
.
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%
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
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: