Answer:
The amount of NaOH required to prepare a solution of 2.5N NaOH.
The molecular mass of NaOH is 40.0g/mol.
Explanation:
Since,
NaOH has only one replaceable -OH group.
So, its acidity is one.
Hence,
The molecular mass of NaOH =its equivalent mass
Normality formula can be written as:[tex]Normality=\frac{mass of solute NaOH}{its equivalent mass} * \frac{1}{volume of solution in L} \\[/tex]
Substitute the given values in this formula to get the mass of NaOH required.
[tex]2.5N=\frac{mass of NaOH}{40g/mol} *\frac{1}{1L} \\mass of NaOH=2.5N*40gmol\\ = 100.0g[/tex]
Hence, the mass of NaOH required to prepare 2.5N and 1L. solution is 100g
3. Which equation shows why nuclear fission can produce a large amount of energy from very little mass?
E= 1/2 mv ^2
E= m^2
E= c^2
E= mc^2
Answer:
E=mc^2 is correct answer, last one
Explanation:
Hope it will help you
a liquid is boiled in a beaker until all of the liquid has evaporated. a powdery substance remains in the beaker. which does this indicate about the original liquid
ASAP PLEASE IM LITERALLY IN THE EXAM RN
From lithium and cesium which is less electronegative?
Answer:Electronegativity, symbolized as χ, is the tendency of an atom to attract shared electrons (or electron density) to itself.
Explanation:
Answer:
Explanation:
The correct answer is cesium
Because If you look at the electronegativities of just Lithium and Cesium then you would notice that the shielding effect is more prevalent in Cesium, thereby reducing the electronegativity and affecting the reduction potential
Witch two chemists organized the elements based on properties suck as how the elements reacts or whether they are solid or liquid
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.
What is the most likely result of the pollution of a fresh water resource?
Answer:
Loss of biodiversity in the wetlands.
Explanation: Pollution can be defined as the emission of toxic, poisonous and harmful chemical substances which are capable of causing environmental degradation and contamination.
Nitrogen pollution enters Earth’s freshwater resources from a variety of human activities, including the use of fertilizers and pesticides in agriculture. This nitrogen pollution has a negative effect on plants and animals living in fresh water. Certain wetland plants, however, are able to purify the water and restore it to its non-polluted state.
Hence, what would most likely increase the negative effects of nitrogen pollution is a loss of biodiversity in the wetlands i.e the various species of animal and plants.
In the early 1600's, Galileo used a telescope to investigate dark features on the Sun's surface and used them to calculate the rate of the sun's rotation. What areas of relatively cool gas were Galileo observing?
prominences
solar flares
photospheres
sunpsots
Answer:
I think its "sunspots"
Explanation:
Which of these is true about a pH meter?
It is inexpensive to use.
It measures pH indirectly.
It does not require calibration.
It can be used in any acid-base titration.
Answer:
That is, a pH meter is useful in detecting or knowing the acidity (due to ions) or alkalinity (due to ions) of a solution. Thus, we can conclude that out of the given options it is true about a pH meter that it can be used in any acid-base titration
Answer: D. It can be used in any acid-base titration.
Explanation:
URGENT PLEASE HELP!
Which statement is true about a basic solution? (5 points)
Its pH is equal to 7.
Its pH is less than 7.
It has the same concentration of hydronium and hydroxide ions.
It has a greater concentration of hydroxide ion than hydronium ions.
Answer:
It has a greater concentration of hydroxide ion than hydronium ions.
how many atoms are in 3 moI of helium
Answer:
1.806x10^24Explanation:
1 mole of helium gas contains 6.02 x10^23 helium atoms. So multiply this by 3 after solving the equation.
22)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
4Fe(s) + 3O2(g) → 2Fe2O3(s)
A)1.2 mol
B)1.8 mol
C)2.4 mol
D)3.2 mol
E)4.8 mol
show work
Answer:
B
Explanation:
)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
B)1.8 mol
The chemical properties of an element are determined by which
particle of an atom?
electron
b
nucleus
оооо
proton
neutron
The chemical properties of an element are determined by which particle of an atom?
[tex]\longrightarrow{\green{c.\:proton}}[/tex]
Explanation:
The chemical properties of an element are determined by the subatomic particle known as a proton. The number of protons in an atom is called its atomic number ( Z ).
[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{♡}}}}}[/tex]
Describe the four states of matter.
Does a reaction involving an acid and a base have to take place in a water environment? Justify your answer.
Answer:
YES!!!
Explanation:
Strong acids and strong bases are both strong electrolytes. In contrast, only a fraction of the molecules of weak acids and weak bases react with water to produce ions, so weak acids and weak bases are also weak electrolytes.
Select all the correct images
Select the atoms that belong to the same element
Answer: Atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.
Explanation:
Elements that contain same number of valence electrons belong to the same group. This is because they will have same reactivity (or properties) due to which they lie in the same group.
For example, element with 11 protons, 10 neutrons and 11 electrons is same as the element with 11 protons, 12 neutrons and 11 electrons.
Hence, both these atoms belong to the same element.
Thus, we can conclude that atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.
Which process will decrease the level of CO2 in the atmosphere?
A.
growing trees
B.
cutting trees
C.
burning trees
D.
increasing the human population
Answer:
A
Explanation:
You will not measure the enthalpy of the reaction of ______ in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
HCI and MgO
HCI and Mg
H2 and O2
Answer:
H2 and O2
Explanation:
A coffee cup calorimeter is basically a type of calorimeter that operates at constant pressure. The heat measured in the calorimeter is equal to the change in enthalpy of the reaction.
This type of calorimeter is apt for reactions involving solutions where there is little or no change in volume.
It is not generally applicable to gas phase reactions such as the reaction between H2 and O2.
Answer:
You will not measure the enthalpy of the reaction of
✔ H2 and O2
in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
C. H2 and O2
Is Correct
How many grams of sodium are needed to produce 12.5g of sodium oxide
Answer:
25 possibly
Explanation:
I'm not too sure about this, but sodium oxide is Na2O, 2 sodium and 1 oxygen, so 12.5g * 2 is 25
If someone else comes up with a more convincing argument listen to them
The electrolysis of water has the equation 2H2O (l) → 2H2 (g) + O2 (g). What type of reaction is this?
Question 9 options:
A)
Single displacement
B)
Double displacement
C)
Decomposition
D)
Synthesis
Answer: The correct option is C) decomposition
Explanation:
Single displacement reaction is defined as the reaction where a more reactive element displaces a less reactive element from its salt solution.
[tex]AX+B\rightarrow BX+A[/tex]
Element B is more reactive than element A
Double displacement reaction is defined as the reaction where an exchange of ions takes place in a solution
[tex]AX+BY\rightarrow AY+BX[/tex]
Decomposition reaction is defined as the reaction where a single large chemical species breaks down into two or more smaller chemical species.
[tex]AB\rightarrow A+B[/tex]
Synthesis reaction is defined as the reaction where two or more smaller chemical species combine together in their elemental state to form a single large chemical species.
[tex]A+B\rightarrow AB[/tex]
For the given chemical reaction:
[tex]2H_2O(l)\rightarrow 2H_2(g)+O_2(g)[/tex]
Here, water is breaking down into two smaller species of oxygen and hydrogen gas. Thus, it is a decomposition reaction.
Hence, the correct option is C) decomposition
Answer:
Decomposition
Explanation:
an atom of an element is represented as 39/19x, write its
(1) number of protons
(2)number of neutrons
(3)Electric configuration
(4)number of valence electrons
Answer:
Solution :
Lithium
Z = 3
P = 3
E = 3 = (2, 1) p=3
A = 7 n=4
P + n = A
3 + n = 7
N = 4

Carbon
Z = 6
P = 6
E = 6 = (2, 4) p=6
A = 12 n=6
P + n = A
6 + n = 12
N = 6
A dryer uses 4200 W and operates for 2.50 hours in one day, how much energy is used?
Answer:
37800KJ
Explanation:
Which of the following describes the reactants of a chemical reaction?
A. The substances that dissolve
B. The resulting substances
C. The atoms that are rearranged
D. The original substances
What plate forms a boundary with the African plate
Answer:
The Eurasian plate(another major plate), the Aegean sea plate and the Anatolian plate share the north border. The Antarctic plate that contributes to the south of the African plate, is also a major plate.
At STP, what is the volume of 55.0 g of BF3?
Answer:
The volume of 55 grams of BF₃ is 18.1664 L.
Explanation:
If the molar mass of compound BF₃ is 67.81 [tex]\frac{grams}{mole}[/tex], then the number of moles 55 grams of compound contains is calculated as:
[tex]55 grams* \frac{1 mole}{67.81 grams} = 0.811 moles[/tex]
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then it is possible to apply the following rule of three: if by definition of STP 1 mole of a compound occupies 22.4 L, 0.811 moles of the compound occupies how much volume?
[tex]volume=\frac{0.811 moles* 22.4 L}{1 mole}[/tex]
volume= 18.1664 L
The volume of 55 grams of BF₃ is 18.1664 L.
? Question
What happens when ionic bonds are formed?
#CarryOnLearning
How much heat is required to raise the temperature of 16.0 grams H2O from 5.000C to 75.00C? Below is a list of constants.
specific heat for H2O(s) = 2.1 J/g0C
specific heat for H2O(L) = 4.18 J/g0C
specific heat for H2O(g) = 1.7 J/g0C
\bigtriangleup H△Hvap = 40.7 kJ/mol
\bigtriangleup H△Hfus = 6.01 kJ/mol
5.34 J
260 J
4680 J
2350 J
Answer:
The amount of heat required is 4681.6 J.
Explanation:
mass, m = 16 g = 0.016 kg
initial temperature, T = 5 C
final temperature, T' = 75 C
specific heat, c = 4.18 J/g C
The amount of heat required is
H = m c (T'- T)
H = 16 x 4.18 x (75 - 5)
H = 4681.6 J
Calculate the total amount of energy required in calories to convert 50.0 g of ice at 0.00 degrees Celsius to steam at 100. degrees Celsius.
Specific heat capacity of water is 1.00 cal/g OC
Hfusion = 80 cal/g OC and Hvap = 540 cal/g OC
Write the complete equation you will use. 1 point
Substitute the values in the equation in step 1. 1 point
Report the math answer with 3 sig figs and the correct unit. 1 point
Answer:
HFusion*mass + Spec.Heat*mass*ΔT + HVap*mass
80cal/g*50.0g + 1.00cal/g°C*50.0g*(100°C-0°C) + 540cal/g*50g
3.60x10⁵cal
Explanation:
Using the HFusion we can find the heat needed to convert the ice to liquid water.
With specific heat capacity we can find the heat needed to increase the temperature of water from 0 to 100°C.
With HVap we can find the heat to convert the liquid water into steam.
The equations are:
HFusion*mass + Spec.Heat*mass*ΔT + HVap*massComputing the values:
80cal/g*50.0g + 1.00cal/g°C*50.0g*(100°C-0°C) + 540cal/g*50g36000cal =
3.60x10⁵calhat is the oxidation state of each element in the compound CaSO4? Include + or - in your answers as appropriate.
The oxidation state of calcium is
.
The oxidation state of sulfur is
.
The oxidation state of oxygen is
HELP ITS IN TBE PICTURE
Answer:
[tex] \small \sf \fbox{Physical Change}[/tex]
Explanation:
Crushing a mineral into powder is a physical change.
Elias read a book about California earthquakes. He then wrote a three-
paragraph report about the book. Which of the following active reading
strategies did Elias use?
A. Making mental images
B. Drawing inferences
C. Summarizing
D. Making predictions
I neeeeed heeeeeelppppppp
Answer:
I think no. 4
Explanation:
It is true that Earth’s orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the Sun than at other times. However, in the Northern Hemisphere, we are having winter when Earth is closest to the Sun and summer when it is farthest away!
There is a completely different reason for Earth's seasons.
Earth's axis is an imaginary pole going right through the center of Earth from "top" to "bottom." Earth spins around this pole, making one complete turn each day. That is why we have day and night, and why every part of Earth's surface gets some of each.
Earth has seasons because its axis doesn't stand up straight
(to be clear I just copied it from some resources)
