Answer:
10.4 M
Explanation:
5.2 Moles / .5 L = 10.4 M
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
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
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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A manufacturer advertises that a particular brand of lotion is “pH balanced” and that it has a pH equal to 6.25. What can you infer about the lotion based on the information in the ad?
We can infer about the given information of lotion is that pH is slightly acidic in nature.
What is pH?pH of any solution gives idea about the acidity or basicity of that solution, and it will be calculated as:
pH = -log[H⁺]
pH value in the range of 0 to 6.9 shows acidity, 7 shows the neutral nature and from 7.1 to 14 shows basicity. Given pH value of lotion i.e. 6.25 states that lotion is slightly acidic in nature.
Hence pH value of lotion informs that lotion is slightly acidic.
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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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What percentage of Americans believes that humans are causing global warming?
10
24
68
93
Answer:
49% say human activitiy contributes global warming.
Answer:
The answer is 68%
Explanation:
including me :)
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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What is the volume occupied by 11 grams of NO2(g) at STP?
Please Help I don’t understand
The volume of gas occupied by 11 grams of nitrogen dioxide gas at STP is 5.15 L.
What is the ideal gas equation?Ideal gas equation of any gas will be writen as:
PV = nRT, where
P = standard pressure = 1 atm
V = volume = ?
R = universal gas constant = 0.082 L.atm/K.mol
T = standard temperature = 273K
n is the moles of gas which can be calculated by using below equation as:
n = W/M, where
W = given mass = 11g
M = molar mass = 46 g/mol
n = 11 / 46 = 0.239mol
On putting values on the above equation, we get
V = (0.23)(0.082)(273) / (1) = 5.15 L
Hence required volume of gas is 5.15 L.
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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.
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 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.
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)
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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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.:
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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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~
A 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.
chemistry question, 20 points, will mark as brainliest if correct:
Answer:
CS2 + 3O2 -> CO2 + 2SO2
Explanation:
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:
Why the positive emulsion for bread is not clear?
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.
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
How many grams of potassium iodide (KI) are required to prepare 50 mL of a 0.30 M
solution?
Answer:
137 g
Explanation:
Since1 L=103 mLyou can say that your sample must contain 550.0mL solution⋅1.50 moles KI103mL solution=0.825 moles KITo convert the number of moles of potassium iodide to grams, use the molar mass of the compound.0.825moles KI⋅166.003 g1mole KI=137 g−−−−−
2.
The simile in stanza 1 (lines 1-6) helps show the speaker -
wants to learn different languages in order to communicate with others
feels torn between two different worlds that have little in common
wants to go home again and not have to speak or listen to anyone
feels annoyed by having to spend so much time listening to others
The simile in stanza 1 (lines 1-6) shows that the speaker:
"feels torn between two different worlds that have little in common" (Option B)
Why does the speaker feel torn between two different worlds?
She speaker feels torn between two different worlds because the two worlds speak different languages.
It is to be noted that a simile is a figure of speech that compares two different things making use of the word "as".
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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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Which are produced when HCl reacts with Ca(OH)2?
Cl2, H3, and CaO
CaCl and H3O
CaO, Cl2, and H2O
CaCl2 and H2O
Answer:
b did the test
Explanation:
did the test
A balanced chemical equation obeys the law of conservation of mass. The reaction of HCl with Ca(OH)₂ is a weak base - strong acid reaction. The products formed are CaCl₂ and H₂O. The correct option is D.
What is a balanced chemical equation?A chemical equation in which the number of reactants and products on both sides of the equation are equal is defined as the balanced chemical equation. The coefficients are the numbers which are added to balance the chemical equation.
The balanced equation for the reaction of HCl with Ca(OH)₂ is given as:
Ca (OH)₂ (s) + 2HCl (aq) → CaCl₂ (aq) + 2H₂O (l)
Here one mole of Ca (OH)₂ reacts with two moles of HCl and gives one mole of CaCl₂ and two moles of H₂O respectively. Here Ca (OH)₂ is a white precipitate and HCl is a aqueous solution.
Thus the correct option is D.
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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)
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
Find the pH of a 0.600 M solution of methylamine CH3NH2. Kb= 4.4 x 10^-4
What is the mass in kilograms of a sample containing 2.4 x 10^{24} atoms of this element? Do not use scientific notation.