Answer:
This means that one mole of water molecules has a mass of 18.015g.
42.3g * 1 mole H2O/18.015g
= 2.3480 moles H2O
We are using the avogadros number to find the number of molecules of water
2.3480 H2O * 6.022*10^ 23moles/ 1mole of H2O
That's 2.3480 multiplied by 6.022*10^23 divided by 1 mole of H2O
Number of molecules = 1.4140 *10^24 molecules
Which of the following is not a characteristic of both experiments and
surveys?
A. Subjects should be randomly selected.
B. The data collected might be studied for patterns.
C. The researcher exercises direct control over at least one variable.
D. Data are collected about a population.
Answer:
C. The researcher exercises direct control over at least one variable.
Explanation:
Your answer should be C. The researcher exercises direct control over at least one variable.
I hope it helps! Have a great day!
pan~
I will mark as brainiest or what ever its called lol. Please helpp
Answer:
A - Cinder cone
B - Shield
C - Composite
Explanation:
Cinder cone volcanoes are formed when the volcano explodes and all the lava soldifies and falls steeply upon the sides of the mountain and forms cinders.
Shield volcanoes form when a centralized vent produces low-viscosity flows over a long period of time
Composite volcanoes are also called stratovolcanoes. They form when different types of eruptions deposit different materials around the sides of a volcano. Alternating eruptions of volcanic ash and lava cause layers to form. Over time these layers build up.
Answer:
Answer:A - Cinder coneB - Shield C - CompositeExplanation:Cinder cone volcanoes are formed when the volcano explodes and all the lava soldifies and falls steeply upon the sides of the mountain and forms cinders. Shield volcanoes form when a centralized vent produces low-viscosity flows over a long period of time Composite volcanoes are also called stratovolcanoes. They form when different types of eruptions deposit different materials around the sides of a volcano. Alternating eruptions of volcanic ash and lava cause layers to form. Over time these layers build up.:
Listed below are the step equations for the reaction in which sulfur dioxide (SO2) and hydrogen disulfide (H2S) react to produce sulfur and water. Write the balanced target equation and use Hess’s law to calculate the ΔH of this reaction.
SO2 (g) → S (s) + O2 (g) ΔH = +300.1 kJ
H2 (g) + S (s) → H2S (g) ΔH = –19.5 kJ
H2 (g) + O2 (g) → H2O (g) ΔH = –290.1 kJ
Based on Hess law, the enthalpy change, ΔH of the reaction is +48.9 kJ.
What is the equation of the reaction?The equation of the reaction of sulfur dioxide (SO2) and hydrogen disulfide (H2S) to produce sulfur and water is given below:
[tex]SO_2 + 2H_2S \rightarrow 3S + 2H_2O[/tex]
The ΔH of the reaction is calculated from the summation of the ΔH of the intermediate reactions according to Hess law.
SO2 (g) → S (s) + O2 (g) ΔH1 = +300.1 kJ
H2 (g) + S (s) → H2S (g) ΔH2 = –19.5 kJ
2H2 (g) + O2 (g) → 2H2O (g) ΔH3 = –290.1 kJ
ΔH of the reaction = ΔH1 + 2(-ΔH2) + ΔH3
ΔH of the reaction = 300 + 2 × -(-19.5) + (-290.1)
ΔH of the reaction = +48.9 kJ
Therefore, the ΔH of the reaction is +48.9 kJ.
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Find the pH of a 0.600 M solution of methylamine CH3NH2. Kb= 4.4 x 10^-4
What is the heat capacity equation?
Answer:
The specific heat capacity is the heat or energy required to change one unit mass of a substance of a constant volume by 1 °C. The formula is Cv = Q / (ΔT ⨉ m)
Write two half‑reactions to describe each of these metal displacement reactions. Include phase symbols.
Mg(s)+CoBr2(aq)⟶MgBr2(aq)+Co(s)
oxidation half‑reaction:
reduction half‑reaction:
Cu(s)+2AuCl(aq)⟶CuCl2(aq)+2Au(s)
oxidation half‑reaction:
reduction half‑reaction:
In redox reactions, an oxidation half reaction shows the oxusetoon occurring while the reduction half reaction shows the reduction occurring in the overall reaction.
What are redox reactions?Redox reactions are reactions in which oxidation and reduction reactions occur together to the same extent.
A redox reaction can be split into two half oxidation and reduction reactions.
The half reactions of the given reactions are shown below:
Overall reaction;
[tex]A. Mg(s) + CoBr_2(aq) ⟶ MgBr_2(aq) + Co(s) \\ [/tex]
Oxidation half reaction:
[tex]Mg (s) ---> Mg ^{2+}(aq)[/tex]
Reduction half reaction:
[tex]Co^{2+} (aq) ---> Co (s)[/tex]
B. Overall reaction
[tex]Cu(s) + 2AuCl(aq) ⟶ CuCl_2(aq) + 2Au(s) \\ [/tex]
Oxidation half reaction:
[tex]Cu(s) ---> Cu^{2+}(aq)[/tex]
Reduction half reaction:
[tex]2Au^{+}(aq) ---> 2 Au (s)[/tex]
Therefore, redox equations can be spilt into oxidation and reduction half reactions.
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I really need to know the answer it will help
Answer:
so the answer is A 5.199mol please. rate. me brainliest. if its. correct
Explanation:
N=nL
[tex]3.131 \times {10}^{24} = n \times 6.022 \times {10}^{23} \\n = \frac{3.131 \times {10}^{24} }{6.022 \times {10}^{23} } \\ n = 5.199mol[/tex]
The Ksp of scandium fluoride, ScF3, is 5.81×10−24. Calculate the molar solubility ,s, of this compound.
The Ksp shows the extent of solubility of a substance in another. The solubility of the compound is 1.2 * 10^-7 M.
What is solubility?The term solubility shows the extent to which a substance dissolve in solution. The solubility of a substance is often typified by the Ksp of the substance.
Now;
ScF3(s) ⇄Sc^+(aq) + 3F^-
Ksp = [Sc^+] [F^-]^3
Ksp = x (3x)^3
Ksp = 27x^4
x = 4√5.81×10^−24/27
x = 1.2 * 10^-7 M
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A sample has 0.2 moles of salt dissolved in 2 L of solution. What is the molarity
The molarity of the sample of the salt dissolved in the solution is determined as 0.1 M.
What is the molarity of the sample?
The molarity of the sample is the number of solutes dissolved in liters solution.
molarity = number of moles/Liters of solution
molarity = 0.2 moles / 2L
molarity = 0.1 M
Thus, the molarity of the sample of the salt dissolved in the solution is determined as 0.1 M.
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#SPJ1
Elements in which family would require the least amount of ionization energy (the
amount of energy used to take away an electron)?
transition metals
Alkali metals
Alkaline earth metals
Alkali metals require least amount of ionization energy.
Peaky Blinder fan? haha
which words in the story help the reader understand the meaning of the word avid in paragraph 1?
The curious and observant are the words in the story which helps the reader understand the meaning of the word avid.
What is Avid?This refers to when an individual is very enthusiastic or interested in something.
In paragraph 1 , the words which makes us understand the word 'avid' is the character being curious and observant which shows there is interest.
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A student places a 50.0 g sample of a metal at 96.8° C into a calorimeter full of 100.0 g of
water (specific heat of water = 4.18 J/g°C). The water, initially at 22.0 °C, eventually
comes to a temperature of 25.9 °C. Calculate the heat gained by the water.
Answer:
1630.2 j
Explanation:
100 gm * 4.18 J/gm-C * ( 25.9-22 C ) = 1630.2 j
A compound has a mass percent composition of 58.8% C, 9.86% H and 31.32% O. The molar mass of the compound is 306.39 g/mol.
(a) Calculate the empirical formula.
(b) Calculate the molecular formula
Enter your answers using the following format for a formula: C3H3O3
The solution would be like this for this specific problem:
Moles of carbon = 58.8 / 12 = 4.9
Moles of hydrogen = 9.8 / 1 = 9.8
Moles of oxugen = 31.4 / 16 m= 1.96
Ratio 4.9 / 1.96 = 2.5 9.8 / 1.96 = 5.0 1.96 / 1.96 = 1
Simplest formula = C5H10
I hope this helps and if you have any further questions, please don’t hesitate to ask again.
How many significant digits are in the following:
pH 7.02
Answer:
3
Explanation:
7.02 three sig digits
What type of reaction is this?
Na(s) + O2(g)
Answer:
Combustion. It is combustion since we assume that it is in a rigid container and Na reacts with oxygen gas
25 points!!!! What’s the answer???
Explanation:
Constructive interference occurs when the maxima of two waves add together (the two waves are in phase), so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes. Equivalently, the minima of the waves would be aligned.
Which molecule would provide the most accurate value for the bond length of a nitrogen-nitrogen double bond
Answer:
i dont know, i wish i could help
Explanation:
The pressure of a nitrogen gas, N2, cylinder is measured at 250 K and found to be 4.0 atm. What is the pressure of the same cylinder at room temperature, 293 K?
Apply Gay lussac's law
P_1T_2=P_2T_14(293)=250P_21172=250P_2586=125P_2P_2=586/125P_2=4.688atmA way of generating dry O2 in the lab is to heat potassium chlorate. If you determined that 25 grams of O, are needed, how much potassium chlorate do you need to start with? 2KCI0, ->(heat)2KCI + 30,
Answer:
About 64 grams of KClO₃.
Explanation:
Potassium chlorate dissociates according to the equation:
[tex]\displaystyle 2\text{KClO$_3$} \xrightarrow{\text{heat}} 2\text{KCl} + 3\text{O$_2$}[/tex]
To determine the amount of KClO₃ necessary to produce 25 grams of O₂, we can convert grams of O₂ to moles; moles of O₂ to moles of KClO₃; and finally to grams of KClO₃.
The molecular weights of O₂ and KClO₃ are 16.00 g/mol and 122.55 g/mol.
Hence:
[tex]\displaystyle 25\text{ g O$_2$} \cdot \frac{1\text{ mol O$_2$}}{32.00\text{ g O$_2$}} \cdot \frac{2\text{ mol KClO$_3$}}{3\text{ mol O$_2$}} \cdot \frac{122.55\text{ g KClO$_3$}}{1\text{ mol KClO$_3$}} = 64\text{ g KClO$_3$}[/tex]
In conclusion, about 64 (to two significant digits) grams of KClO₃ is needed.
what foods can be stored in water and or ice
How much time would it take for 40000 atoms of sodium-24 (half-life is 15 days) to decay to 2500 atoms?
Answer:
60 days
Explanation:
2500 = 40000 ( 1/2) ^n
n = 4 half lives
4 half lives * 15 days/ halflife = 60 days
Which adaptation do polar bears and camels have in common?
A. Thick layer of body fat for food storage and insulation.
B. A small surface area to volume to reduce heat loss.
C. Thin fur and little body fat.
D. Large feet to spread body weight.
Answer:
Thick layer of body fat for food storage and insulation
Explanation:
Polar bears store food for themselves and so do camels. Option B is not correct because bears do not definitely have small surface area and even if camels do they do not need to reduce heat loss because they stay in the deserts. For option C polar bears have thick fur and much body fat to protect itself from the cold. Lastly D cannot be true because camels don't normally have large feet they have small padded foot.
Soil that are light in color have a great amount of humus in
them. True or False
Answer:
please the answer Is false
By examining electron domain geometry, one can determine that the ammonia molecule (NH3) has
Answer:
The ammonia molecule is a trigonal pyramidal and has 4 sp3 orbitals
Explanation:
Nitrogen has 5 valence electrons, Hydrogen takes up 3 bonds and there's a lone pair on top, and the gemoetry is structured in a way so the hydrogen atoms are facing down away from the lone pair and evenly spaced out between the other hydrogens.
25 points!!! What’s the answer???
Answer:
C
Explanation:
Cause wave's get larger and larger and it will repeat over and over
(please mark me brainly est)
Which feature of the state means absolute authority within the country?
Sovereignty is the ultimate authority, in the decision-making process of the state and in the maintenance of law and order.
What is sovereignty?Sovereignty refers to authority within an individual consciousness or territory. Sovereignty entails hierarchy within the state and also for external autonomy for states.
So we can conclude that sovereignty is the ultimate authority, in the decision-making process of the state and in the maintenance of law and order.
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Magnesium ribbon with a mass of 2g was placed into dilute hydrochloric acid. The
equation for this reaction is:
Mg(s) + 2HCI = MgCl2(aq) + H2(g)
The magnesium ribbon reacted and completely disappeared in 30 seconds. Calculate
he rate of reaction.
The rate of reaction of the magnesium ribbon in the dilute hydrochloric acid is 0.067 g/s.
What is rate of reaction?
Rate of reaction is the rate at which a reaction takes place. It is proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time.
Mg(s) + 2HCI = MgCl2(aq) + H2(g)
Rate of reaction = mass of magnesium reacted/time taken
Rate of reaction = 2 g /30 s
Rate of reaction = 0.067 g/s
Thus, the rate of reaction of the magnesium ribbon in the dilute hydrochloric acid is 0.067 g/s.
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Why the positive emulsion for bread is not clear?
In a neutralization reaction 30.0mL of 0.234M KOH solution is reacted with 30.0mL of 0.234M HNO3 solution and a temperature rise of 5.6C was observed. Density of base and acid=1.00g/mL and the specific heat of the mixture is 4.18j/g•C
a) write the balanced equation of the reaction
b) calculate the moles of water produced
c) calculate the total heat produced
d) calculate the enthalpy of neutralization of the reaction
Based on the data provided, the equation of the reaction is:
[tex]KOH + HNO_3 \rightarrow KCl + H_2O[/tex]moles of water produced = 0.00702 molesHeat produced = 1404.48 JEnthalpy of neutralization = 200 kJ/molWhat is enthalpy of neutralization?Enthalpy of neutralization is the heat change when one mole of hydrogen ions from an acid reacts with one mole of hydroxide ions from an alkali to produce one mole of water.
The equation of the reaction of KOH and HNO3 is given below:
[tex]KOH + HNO_3 \rightarrow KCl + H_2O[/tex]
1 mole of KOH reacts with 1 mole of HNO3 to produce 1 mole of water.
Volume of KOH = 30 mL = 0.03 L
moles of KOH = 0.03 × 0.234 = 0.00702 moles
Therefore, 0.00702 moles of water are produced
Heat produce = mass × specific heat × temperature difference
Volume of solution = 60 mL
density of solution = 1.0 g/mL
mass of solution = 60 mL × 1.0 g/mL = 60 g
Heat produced = 60 × 4.18 × 5.6
Heat produced = 1404.48 J
Enthalpy of neutralization = 1404.48 J/0.00702 moles
Enthalpy of neutralization = 200068.37 J/mol
Enthalpy of neutralization = 200 kJ/mol
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In the reaction of nitrogen gas, N2, with hydrogen gas, H2, to form ammonia gas, NH3 , how many moles of hydrogen are needed to react with two moles of nitrogen
Answer:
6 moles
Explanation:
First find the balanced equation for the rxn
N2 + 3 H2 ===> 2 NH3
each mole of N2 requires 3 moles of Hydrogen
so 6 moles of H needed