Answer:
Pure water is a non conductor of electricity and dilute acids in their aqueous solutions form free ions, which conducts electricity. Thus when we need to electrolyse water, a dilute acid is added to increase its conductivity.
Oxygen gas in a gas tank has an inital temperature of 325 K, and a pressure of 5 atm. If the gas is cooled to 280K, what will the new preasure be? (Gay-Lussac's Law)
Answer:
Final pressure = [tex]4.31atm[/tex]
Explanation:
According to Gay-Lussac's law the pressure of a given mass of gas varies directly with the absolute temperature of the gas, provided the volume is kept constant.
SEE THE ATTACHMENT BELOW FOR STEP BY STEP EXPLANATION
49 grams of sulfuric acid, H2SO4, is dissolved in 1 liter of solution. Determine the molarity (M).
Answer: .5m
Explanation:
Which is the correct skeleton equation for water + sodium sod hydroxide + hydrogen ?
Answer:
H₂O + Na → NaOH + H₂
Explanation:
Firstly, a skeleton equation does not reflect the relative amount of reactants and products. A skeleton reaction only identifies the reactant and product by their chemical formula but it does not quantify them. A skeleton chemical equation is simply described as an unbalanced equation.
The question asked for the correct skeleton reaction of water and sodium to produce sodium hydroxide and hydrogen.
Let us represent them with their chemical formula
Water → H₂O
Sodium → Na
Sodium hydroxide → NaOH
Hydrogen → H₂
The skeleton reaction will be
H₂O + Na → NaOH + H₂
1) If heating 1Kg of water, how much would the temperature increase by burning 100g of each substance each substance:
a) Ethanol: ∆H= 29.65KJ/g
b) Hexane: ∆H= 48.29KJ/g
c) Kerosene(C12H26): ∆H= 46.2KJ/g
d) Car Fuel (90% octane): ∆H= 47.3KJ/g
e) Diesel (C12H23): ∆H= 44.8KJ/g
Answer:
a) The temperature of the water will rise by maximum 100 K, steam by 143.9 K
b) The temperature of the water will rise by maximum 100 K, steam by 1077.45 K
c) The temperature of the water will rise by maximum 100 K, steam by 972.75 K
d) The temperature of the water will rise by maximum 100 K, steam by 1027.86 K
e) The temperature of the water will rise by maximum 100 K, steam by 902.6 K
Explanation:
a) ΔH for ethanol = 29.65 kJ/g therefore, burning 100 g will produce;
29.65 × 100 = 2965 kJ
The specific heat capacity of water = 4.184 J/(g·K)
Therefore, 2965000= 1000 × 4.184 × ΔT
ΔT = 2965000 ÷ (1000 × 4.184) = 708.65 K
Latent heat of water = 2260 kJ/kg will be absorbed when the temperature reaches the boiling point of water hence we have
2965 - 2260 = 705 kJ to heat the water of which a maximum of 418.4 will boil the water and the steam temperature will rise by (705-418.4)/1.996 = 143.59 K
b) For Hexane: ΔH = 48.29 kJ/g
100 g will produce 4829 kJ
∴ Temperature change for the 1 kg water is given as follows
ΔT = 4829000 ÷ (1000 × 4.184) = 1154.16 K
However
4829 - 2260 = 2569
2569 - 418.4 = 2150.6
2150.6 / 1.996 = 1077.45 K
The final steam temperature will rise by 1077.45 K
c) For Kerosene(C₁₂H₂₆): ΔH = 46.2 kJ/g
100 g will produce 4620 kJ
∴ Hypothetically the temperature change for the 1 kg water is given as follows
ΔT = 4620000 ÷ (1000 × 4.184) = 1104.21 K
However
4620 - 2260 = 2360
2360 - 418.4 = 1941.6
1941.6 / 1.996 = 972.75 K
The final steam temperature will rise by 972.75 K
d) For Car Fuel(90% octane): ΔH = 47.3 kJ/g
100 g will produce 4730 kJ
∴ Temperature change for the 1 kg water is given as follows
ΔT = 4730000 ÷ 4184 = 1130.5 K
However
4730 - 2260 = 2470
2470 - 418.4 = 2051.6
2051.6 / 1.996 = 1027.86 K
The final steam temperature will rise by 1027.86 K
e) For Diesel (C₁₂H₂₃): ΔH = 44.8 kJ/g
100 g will produce 4480 kJ
∴ Temperature change for the 1 kg water is given as follows
ΔT = 4480000 ÷ 4184 = 1070.75 K.
However
4480 - 2260 = 2220
2220 - 418.4 = 1801.6
1801.6 / 1.996 = 902.6 K
The final steam temperature will rise by 902.6 K.
______________ have properties of both metals and non metals.
Answer:
gold
Explanation:
PLS HELP NOW WILL GIVE BRAINLIEST
liquids have:
A. fixed size and shape
B. fixed size but not fixed shape
C. neither fixed size or shape
Answer:
Liquids, because they flow, can occupy whatever shape their container has, so they do not have a fixed shape. Because the particles in liquids are very close together (barely further apart than in solids) liquids do not easily compress, so their volume is fixed. hope that helps love!
Which part of the calcium atom in the ground state is represented by the dots in its Lewis electron dot diagram
Answer:
On the left side of calcium atom.
Explanation:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom. if the calcium atom loses these two electron during a chemical reaction so the two dots disappear and the calcium atom is now stable.
Answer:
the electrons in the fourth shell
Explanation:
the Lewis electron dot diagram represents the valence electrons, in the case of calcium, the V.E. are in the fourth shell
Calcium has two electrons in its outer level. What will it most likely do in a reaction?
try to give away its two outer electron to another atom
try to pick up 6 electrons from another atom or two
try to pick up 2 electron from another atom to fill the 4s sublevel
nothing because it is perfectly stable.
Answer:
try to give away its two outer electron to another atom
Explanation:
which indicator has to be used in order to get an emerald green color at a pH of 9?
a) universal indicator
b) methyl orange indicator
c) thymol blue indicator
d) cyanidin
Answer:
D) Cyanidin indicator
Explanation:
Cyanidin indicator has to be used in order to get an emerald green color at a pH of 9.
What is an indicator?Indicators are substances that change colour when they are added to acidic or alkaline solutions.
In nature, cyanidin is a reddish-purple (magenta) pigment. It is the major pigment in berries [4] and other red-coloured vegetables such as red sweet potato and purple corn. It appears as a blue-reddish or purple pigment in the plant.
Cyanidin indicator has to be used in order to get an emerald green colour at a pH of 9.
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why is it difficult to obtain oxygen from water
Answer:
Combined with Hydrogen
Explanation:
write the full form of the following LPG and CNG
Answer:
LPG -Liquefied Petroleum Gas. CNG-Compressed Natural Gas.
May this help you
Hey!!!
LPG=Liquified Petroleum Gas
Or,
Liquid petrol Gas
CNG=Compressed Natural Gas
Hope it helps....
Good luck on your assignment
Newton’s first law of motion states that an object at rest stays at rest,and an object in motion stays in motion,unless acted on by an unbalanced force.
Answer: yes that is true
Explanation:
newtons first law does state that.
Answer:
1. An overall net force must be applied to an object before it can move.
2. Newton’s first law of motion is also known as the law of inertia.
3. Newton’s first law applies to an object whether it is moving or not.
Explanation:
Edge
In a chemical reaction equation, which side of the arrow is the reactant?
" A+B --> AB"
- left
- right
- there are no reactants in equations.
Answer:
Left.
Explanation:
A+B --> AB
reactants product
The following equation is an example of what type of reaction? " A+B --> AB - decomposition - catalyst - chain reaction - combination/ synthesis
Answer:
The equation is an example of combination/synthesis.
Explanation:
A + B → AB
The definition of synthesis is the act of simpler compounds being combined together to make a more complex compound. Both A and B are being combined to each other to make AB. So, the given equation shows a synthesis reaction.
which of the following best describes what a scientist does
This might help you with your question.
This is a person who scientific researches to make more knowledge in a certain area of interest
which value is expected to be the largest? heat of fusion, heat of vaporization, specific heat of a liquid, specific heat of a solid, or specific heat of a gas?
Answer:
Heat of fusion
Explanation:
20 points!! Please help me! Will mark Brainliest!! complete the following word equations:) also write the balanced equation, full ionic equation, and net ionic equation. Also include the states:)
a) zinc nitrate + calcium sulphide—>
b) potassium + calcium chloride—>
Answer:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The total ionic equations shows the equation in which all the species of the reactants and the products are in dissociated form and are represented as ions.
The net ionic equations shows the equation in which all the species of the reactants and the products are in dissociated form and do not show the spectator ions which are same in the reactants and the products.
a) zinc nitrate + calcium sulphide [tex]\rightarrow [/tex] zinc sulphide + calcium nitrate
balance equation : [tex]Zn(NO_3)_2(aq)+CaS(aq)\rightarrow ZnS(s)+Ca(NO_3)_2(aq)[/tex]
total ionic equation :
[tex]Zn^{2+}(aq)+2NO_3^-(aq)+Ca^{2+}(aq)+S^{2-}(aq)\rightarrow ZnS(s)+Ca^{2+}(aq)+2NO_3^-(aq)[/tex]
net ionic equation :
[tex]Zn^{2+}(aq)++S^{2-}(aq)\rightarrow ZnS(s)[/tex]
b) potassium + calcium chloride [tex]\rightarrow [/tex] potassium chloride + calcium
balance equation : [tex]2K(s)+CaCl_2(aq)\rightarrow 2KCl(aq)+Ca(s)[/tex]
total ionic equation :
[tex]2K(s)+Ca^{2+}(aq)+2Cl^-(aq)\rightarrow 2K^+(aq)+2Cl^-(aq)+Ca[/tex]
net ionic equation: [tex]2K(s)+Ca^{2+}(aq)+\rightarrow 2K^+(aq)++Ca[/tex]
How did plastics become the material of choice for so many varied applications?
Answer:
people as: it Is less expensive. easy to carry
jamie is not sure a new medication will work because it has not had a large test group. Is jamie being creative?
Answer:
yes because I wouldn't do it
Which of the following best describes a possible carbon compound?
Answer:One carbon atom forms a double bond with an oxygen atom and two single bonds with two hydrogen atoms
Explanation:
the chemical equation for reduction of phosphorite Ca3(PO4)2
Answer:
The chemical equation is;
Ca3(PO4)2 + 8C ———> Ca3P2 + 8CO
Explanation:
Here, we are interested in writing a chemical equation that is useful in the reduction of phosphorite.
We should understand that to be able to reduce phosphorite, there is need for a reducing agent.
Solid carbon can be used here.
The products formed are shown in the equation as follows;
Ca3(PO4)2 + 8C ———> Ca3P2 + 8CO
110. A sports drink" contains 55 mg of potassium ions per 400 ml
serving. Calculate the concentration of the potassium ions in ppm.
Answer:
The concentration of the potassium ions in ppm is 137.5 ppm
Explanation:
Here, we are interested in calculating the concentration of the potassium ions in ppm.
Mathematically, the term ppm which is read as parts per million is = mg of solute/liter of solution
We already have the mg of solute as 55mg
all we need now is the liters of solution
But what we have is 400 ml which is read as 400 milliliters
Mathematically, 1000 ml = 1l
Thus 400 ml = 400/1000 L = 0.4 L
Now the ppm = 55mg/0.4L = 137.5 mg/L or simply 137.5 ppm
Identify the correct same regarding the strength of chemical bonds
A. Strong bonds require less energy in the form than weak bonds
B.Weak bonds require less energy to Form bonds than strong bonds
C. Strong bonds occur with high temperature and weak bonds with low temperature
D. Weak bonds require more key to formed and strong bonds
Answer:
weak bonds require less energy to form bonds than strong bonds
What's the molarity of the solution containing 10 g of NaCN in 250 mL of solution?
Answer:
0.816
Explanation:
1 mole of NaCN is
Na = 23
C = 12
N = 14
Total = 49 grams / mole (just add 23 + 12 + 14)
moles when only 10 grams of NaCN are used.
moles = grams/molar mass
grams = 10
molar mass = 49
moles = 10 / 49
moles = 0.204 moles
Volume in Liters
250 mL = 250mL/1000 mL / Liter = 0.25 Liters
Molarity
M = m/V
M = 0.204/0.25 = 0.816
what is the gram formula mass for Mg(OH)2
Answer:
58.33 g/mol
Explanation:
What does the kinetic theory state?
What is the perecentage yield of a reaction in which 200g PCl3 reacts with excess water to form 128g HCl according to the f.F reaction? PCl3 +3H2O=H3PO3+ 3HCl
Answer:
The percentage yield is 80.36% (see calculations in attachment).
Explanation:
The theoretical yield of the reaction is the amount of product that would result if all the limiting reagent reacted. The theoretical yield is calculated using the balanced equation.
In practice, the actual yield, or the amount of product actually obtained from a reaction, is almost always less than the theoretical yield.
To determine how efficient this reaction is, we need to calculate the percent yield, which describes the proportion of the actual yield to the theoretical yield. It is calculated as follows:
[tex] %yield = actual yield ÷ theoretical yield × 100% [/tex]
First we need to make sure that the equation is properly balanced. In the question they provide the balanced equation.
Since water is in excess, we calculate the theoretical yield using PCl₃.
The force between two objects each of charge +Q Is measured as +F when the objects are separated distance d apart. If the charge on each object is double determine the new force between them
a) +2F
b) +4F
c) +1/2F
d) +1/4F
Answer:
B
Explanation:
By using coulombs law meaning the amount of force between two stationary electrically charged particles
Which method of moving materials in and out of a cell requires energy?
active transport
passive transport
osmosis
diffusion
Answer:
Active Transport
Explanation:
As the name suggests, in active transport you need energy to move materials in and out. Similar to how if you want to be active you need energy, same goes with movements in our cells as well.
Which of the following of Dalton's theories do we no longer use today?
atoms of the same element are identical in size, mass, and properties
matter is composed of small tiny particles called atoms
in chemical reactions, atoms are separated, combined, or rearranged
atoms are combined in whole number ratios
Statement of Dalton's theory which is no longer used today is that matter is composed of small tiny particles called atoms as there are sub-atomic particles which are discovered.
What is matter?Matter is a substance which is made up of various types of particles which occupy space and have inertia . All living things and objects are made up of various types of particles that occupy space and have inertia .
Depending on temperature and other factors matter is able to exist in different phases. Most common of which are solid, liquid and gas. Matter can exist in more than one state depending on the temperature and pressure .
State of matter can be changed by heating or cooling and even by changing the applied pressure.When a state changes matter does not break rather its state changes though its chemical composition remains same.
Physical characteristics of matter are shape, color, size and temperature. Every matter is made up of elements which cannot be broken down further by ordinary chemical reactions.
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