Answer:
5.0 moles
Explanation:
213/390 x 9.22 = 5.04
Round to least sig fig (390 ml)
5.0
How much energy (in KJ) is needed to melt 15g of ice at -4oC and raise it to a temperature of 115oC? Round the closest number, and include units
Answer:
The energy needed is 45.7659 kJ
Explanation:
The given mass of the ice, m = 15 g
The initial temperature of the ice, T₁ = -4°C
The temperature
The final temperature, T₂ = 115°C
The specific heat capacity of ice, c₁ = 2.09 J/(g·°C)
The latent heat of ice, l₁ = 334 J/g
The heat capacity of water, c₂ = 4.184 J/(g·°C)
The latent heat of vaporization, l₂ = 2260 J/g
The specific heat of steam, c₃ = 2.02 J/g
Therefore, we get the energy needed, ΔQ, as follows;
ΔQ = m·c₁·(T₂ - Tₐ) + m·l₁ + m·c₂(Tₓ - Tₐ) + m·l₂ + m·c₃·(T₂ - Tₓ)
Where;
Tₐ = The melting point temperature of water = 0°C
Tₓ = The boiling point temperature of water = 100°C
∴ ΔQ = 15×2.09×(0 - (-4)) + 15 × 334 + 15×4.184×(100 - 0) + 15×2260 + 15×2.02×(115 - 100) = 45,765.9
The energy needed, ΔQ = 45,765.9 J = 45.7659 kJ.
ANSWER FAST PLEASE!
Balance the following equation:
__Hg + __O₂ --> __HgO
Answer:
4Hg+2O2=4HgO
four Mercury + four oxygen
Which description applies to all atoms of an element? flammable visible under a microscope different alike
Answer:
I think its alike.... Pretty sure actually
Potassium hydrogen phthalate, KHP, is used as a primary standard for determining the concentration of a solution of NaOH by titration. If the KHP has not been dried before weighing, the calculated molarity of the NaOH would be
A) higher than the actual value, since water is included in the apparent mass of KHP
B) higher than the actual value, since the presence of water requires a larger volume of titrant
C) lower than the actual value, since NaOH absorbs water
D) unaffected, since KHP is a strong acid
E) unaffected, since water is routinely added before the titration
Answer:A
Explanation:
If the KHP has not been dried before weighing, the calculated molarity of the NaOH would be higher than the actual value, since water is included in the apparent mass of KHP.
The KHP is Potassium hydrogen phthalate. It is commonly used as a primary standard in pure form for sodium hydroxide titrations because it is stable in air making it easy to weigh.
However, if KHP is not dried very well, the mass of water is included as part of the mass of KHP and this will make calculated molarity of KHP to be higher than the actual value.
Again, the reaction between KHP and NaOH has a 1:1 molar ratio so if the molarity of KHP is higher than its actual value, the molarity of the NaOH would also be higher than the actual value.
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Turtles are cold blooded, meaning they use the Sun to keep warm. A student hypothesizes that his pet turtle will prefer swimming in warm water. He places his turtle on a rock in the middle of the bathtub, and measures how much time the turtle spends off of the rock during a five minute period. He conducts the experiment under four conditions in the bathtub: no water, warm water, cool water , and room temperature water. In this experiment, which is the control group ?
Answer:
Room temperature water
Explanation:
Neither the amount of water nor the temperature of the water has been changed.
given a mixture of lead to oxide ammonium chloride and sodium chloride describe how a mixture can be separated to obtain a sample each
Answer:
There are way in separating mixtures of chloride salts such as that of sodium chloride and ammonium chloride. It can be done by crystallization, filtration, and sublimation. The easiest method among the three is separation by sublimation.
in what group and periods is most reactive metals
Will give brainliest!
How does the melting of ice caps near the North Pole affect the salinity of the ocean?
Salinity decreases because freshwater flows into the ocean
Salinity increases because of the stored pockets of air and salt
Salinity increases because salt from the ice caps flows into the ocean
There is no change in the ocean’s salinity with this process
Answer:
A.
Explanation:
melting of ice will increase water in oceans due to which water in oceans will increase and salinity will decrease. hence, melting of ice caps near the north pole affects salinity of the ocean
What are the materials that good conductors and insulators?
Conductors
Silver
Gold
Copper
Aluminum
Mercury
Steel
Iron
Seawater
Concrete
Mercury
___________________
insulators
Aluminum foil
Glass
Air
Plastic
Rubber
Porcelain
Wood
What do sex hormones do?
Answer:
Hormones help regulate many bodily processes, such as appetite, sleep, and growth. Sex hormones are those that play an essential role in sexual development and reproduction. The main glands that produce sex hormones are the adrenal glands and the gonads, which include the ovaries in females and testes in males
Explanation:
I'm timed! Select the STEM-related activities performed in the fashion industry.
garment weaving
market analysis
pattern making
fabric dyeing
product promotion
product advertising
Answer:
All of them I think
Explanation:
STEM is science, technology, engineering and math, and all of them use that in some aspect
What is the concentration of a solution made by dissolving 0.99mol of acetic acid in enough water to make 0.58L of solution?
Answer:
[CH₃COOH] = 1.70 M
Explanation:
When we talk about concentration we can determine Molarity
Molarity determines the moles of solute that are contained in 1L of solution.
In this case our solute is the acetic acid.
M = mol/L
M = 0.99 mol /0.58L → 1.70 M
We can also make a rule of three
In 0.58 L of solution we have 0.99 moles of solute
In 1 L of solution we may have (1 . 0.99) / 0.58 = 1.70 moles
Acetic acid is a weak acid, partially dissociated in water.
CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺ Ka
HELP ME WITH THIS PLSSSSS
Answer:Predatorrrrrrrrrrrrrrrr
Pls gimme Brainliest
H2 + O2 + H2O how do I balance this?
Explanation:
[tex]2H _{2(g)} + O _{2(g)}→2H _{2}O _{(l)}[/tex]
Insert 2 on Hydrogen then a 2 on water molecule.
I NEED THIS ASAP Someone please help me
Read the chemical equation. 2NaOH + H2SO4 → Na2SO4 + 2H2O Which of the following statements would be correct if four moles of NaOH were used in this reaction?
A. Two moles of water were produced from this reaction.
B. Four moles of water were produced from this reaction.
C. One mole of H2SO4 was used in this reaction.
D. Eight moles of H2SO4 were used in this reaction.
Answer:
the answer is B
Explanation:
Answer: B!
Explanation:
B. Four moles of water were produced from this reaction.
got it right on the test :-)
The initial temperature of a reaction is 24.7 °C. The temperature decreases by 3.2 °C. What is the new temperature of the reaction? Someone help
Answer:
I think it's 21.5 *C
Explanation:
An object has an actual mass of 34.85 grams. Johnny measures the object to have a mass of 35 grams after rounding. What is Johnny's percent error of the object?
Answer:
1.15.........................
The ____ are a windless zone.
Answer:
sorry I don't know I just came for points
Explanation:
Element 2 is:
A) Cobalt
B)Chlorine
C)Calcium
D)Carbon
Answer:
D: Carbon
Explanation:
Carbon is the sixth element with a total of 6 electrons in the periodic table. Hence the atomic number Z = 6. The ground state electron configuration of carbon is 1s2 2s2 2p2. An excited state electron configuration of carbon is 1s2 2s1 2p3.
How many liters of water would you need to add to 4.36 moles of NaCl to create a 4 M solution?
Explanation:
1 M = 1 mol/L
4.36 mol NaCl ×(1L H20 / 4 mol NaCl) = 1.09 L H20
Answer:
1.09 L of water
Explanation:
4.36 mol NaCl ×(1L of H20 / 4 mol NaCl) = 1.09 L of water
You're provided a 0.50 M solution of HCl. How many moles of HCl are present in 25 ml of this solution?
Answer:
0.0125 moles of HCl
Explanation:
(0.50 mol/L)(0.025 L) = 0.0125 moles of HCl
True or False? In the quantum model of the atom, with its s, p & d orbitals, these circles represent the paths on which the electrons travel as they go around the nucleus
Please i am being timed please help
help me get this right no links
2. A dark shadow covers a small part of the Sun's surface.
(HAVE A GOOD DAY!!)
PLEASE HELP!
See picture
Answer:
See Explanation
Explanation:
The equation of the reaction;
KHSO4(aq) + KOH(aq) -------> K2SO4(aq) + H2O(l)
Number of moles of KHSO4 = 49.6 g/136.169 g/mol = 0.36 moles
Since the reaction is in a mole ratio of 1:1, 0.36 moles of K2SO4 is produced.
Number of moles of KOH = 25.3 g/56.1056 g/mol = 0.45 moles
Since the reaction is 1:1, 0.45 moles of K2SO4 is produced
Hence K2SO4 is the limiting reactant.
Mass of K2SO4 formed = 0.36 moles of K2SO4 * 174.26 g/mol = 62.7 g
So;
1 mole of KHSO4 reacts with 1 mole of KOH
0.36 moles of KHSO4 reacts with 0.36 * 1/1 = 0.36 moles of KOH
Amount of excess KOH = 0.45 moles - 0.36 moles = 0.09 moles
Mass of excess KOH = 0.09 moles * 56.1056 g/mol = 5 g of excess KOH
Using the terms "breaking and making bonds", explain the net energy change for the chemical reaction
between water and ammonium nitrate.
How many grams are in 5.4 moles of K2SO4
Answer:
The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles K2SO4, or 174.2592 grams.
Explanation:
The potassium sulphate( [tex]K_{2} SO_{4}[/tex] )contain 940.95 gram in 5.4 moles.
What is mole?A mole is described as the quantity of a material that includes precisely 6.02214076 X [tex]10^{23}[/tex] of the substance's elementary constituents.
Given data:
Mole = 5.4
Molar mass = 174.25 g/mol
Mass = ?
Mole can be calculated by using the formula:
Mole = mass / molar mass
Put the value of given data in above equation.
Mass = Mole × molar mass
Mass = 5.4 mole × 174.25 g/mol
Mass = 940.95 gram
Therefore, there are 940.95 gram in [tex]K_{2} SO_{4}[/tex]
To know more about mole.
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What likely caused these different results?
Answer:
hope help you stay happy
Help please !!!!!!!!!!!!
the answer to your question is a increase
Mg (s) + 2 HCl (aq) --> MgCl2 (aq) + H2 (g)
Use the equation above to determine the number of grams of magnesium chloride, MgCl2 , that can be produced if 4.00 moles of HCl (hydrochloric acid) react. please show all work and record your answer with proper units and significant figures.
Pls help
Answer:
m = 190. g MgCl2
Explanation:
Use a molar ratio to get the # of moles MgCl2 produced from 4.00 mol of HCl:
4.00 mol HCl × (1 mol MgCl2/2 mol HCl) = 2.00 mil MgCl2
So 2.00 moles of MgCl2 will be produced. To find the mass in grams, use the molar mass of MgCl2:
2.00 mol MgCl2 × (95.211 g MgCl2/1 mol MgCl2)
= 190. g MgCl2
HURRY!!!
What can you infer about the growth of the seed represented in the graphs below?
Answer:
B
Explanation: