Answer: There are [tex]1.415\times 10^{23}[/tex] molecules in 25.4 g of [tex]N_2O_5[/tex]
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{25.4g}{108g/mol}=0.235moles[/tex]
1 mole of [tex]N_2O_5[/tex] contains = [tex]6.023\times 10^{23}[/tex] molecules
Thus 0.235 moles of [tex]N_2O_5[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.235=1.415\times 10^{23}[/tex] molecules.
There are [tex]1.415\times 10^{23}[/tex] molecules in 25.4 g of [tex]N_2O_5[/tex]
Calculate the concentration, in moles per litre, of a solution formed when 13.0 g of calcium hydroxide is dissolved in 5.0 L. Please show work!
Answer: The concentration, in moles per litre, of a solution formed when 13.0 g of calcium hydroxide is dissolved in 5.0 L is 0.036 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of [tex]Ca(OH)_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{13.0g}{74g/mol}=0.18mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.18}{5.0L}=0.036M[/tex]
Therefore, the concentration, in moles per litre, of a solution formed when 13.0 g of calcium hydroxide is dissolved in 5.0 L is 0.036 M
What are the positions of the sun, moon, and Earth relative to each other when we have stronger tides?
What kind of bonds are hydrogen bonds?
Answer:
electromagnetic attraction between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen. I hope that was the answer u was looking for
Answer:
A hydrogen bond is the electromagnetic attraction between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen.
Explanation:
As the temperature of the water increases, what happens to the number of water particles in a mL (cm3)?
Suppose you need to heat food. What wave type from the electromagnetic spectrum could you use?
Answer:
Microwave radiation
Explanation:
This radiation is the one used in microwaves.
Answer:
Infrared
Explanation:
Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark. Infrared light has frequencies which are absorbed by some chemical bonds. The internal energy of the bonds increases when they absorb infrared light, which causes heating.
Titanium will react with magnesium oxide but sodium reacts with titanium oxide.
The position of titanium will be
a. above sodium
b. .below magnesium but above iron
c. below sodium but above magnesium
d.. below silver
Answer:
below sodium but above magnesium
Explanation:
It is necessary to note that only a metal that is above another metal in the activity series can displace it from its compound.
The first statement said that titanium reacts with magnesium oxide. The implication of this is that titanium can displace magnesium from its oxide. This is only possible if titanium is above magnesium in the activity series.
The second statement says that sodium reacts with titanium oxide. This implies that sodium metal can displace titanium from its oxide. For this to occur, then sodium must be above titanium in the activity series of metals. Hence the answer above.
Write the symbol for the ion with 68 electrons, 72 protons, and 106 neutrons.
Answer:
I think it should be Hafnium which is Hf.
Which is a characteristic of the polar water molecule?
.
a tetrahedral electron domain geometry with covalently bonded atoms
a tetrahedral electron domain geometry with ionically bonded atoms
a linear shape with polar covalent bonds
a linear shape with polar ionic bonds
Answer:
A tetrahedral electron domain geometry with covalent bonded atoms.
What is solubility?
- A solution in which no more solute will dissolve.
- The amount of solute it takes to make a supersaturated solution.
- The amount of solute that will dissolve in a given amount of solvent.
- The amount of solvent it takes to dissolve 100 g of solute.
Answer:
the correct answer is c
Explanation:
Which describes the pH of an antacid that is used to neutralize stomach acid?
Answer:
calcium carbonate, is 9.91
Explanation:
Answer:
B or The antacid is basic and will neutralize the acid entering the esophagus.
Explanation:
Which of these metals is least likely to be involved in chemical reactions?
A. iron
B. tin
C. gold
D. copper
Answer:
C gold
Explanation:
How does a catalyst increase the rate of a reaction?
A) It decreases the enthalpy change of the reaction.
B) It lowers the potential energy of the reactants.
C) It provides a lower activation energy for the reaction.
D) It raises the potential energy of the products.
Answer:
C) It provides a lower activation energy for the reaction is the correct answer.
Explanation:
A catalyst increases the rate of the chemical reaction by lowering the activation energy for a reaction.Catalyst is used to increase the reaction rate, it remains unchanged in the chemical reaction and it does not change the equilibrium constant.Activation energy is a minimum amount of energy required to initiate the reaction.Someone can help me whit this? I have the whole document too.
Answer:
1a. Metalloids have properties that are between metals and non-metals, they are alo known as semi-metals.
b.) The yellow border consisting of silicon, boron, Ge As, etc., are metalloid elements
2a.) Non-metals are on the right side of the periodic table.
B.) Non-metals have poor conductivity, are not malleable or ductile, are not sonorous. They are basically the opposite of metals.
Imagine that hotter magma is lying beneath an area of cooler magma deep in the mantle. What do you predict will happen?
Answer:
it will explod because off all of the prussere but on to it.
Explanation:
Pls help me on this question????
Explanation:
The first one is series circuit as it is joined one after another while the second one is parallel circuit joined in a parallel way. Ok the line just like this --------- is the wire , the sign like this | | is the battery and the circles with cross are the bulbs
Hope this helps :) Have a great day
11. What is the mass number
of an element if its atom
contains 10 protons, 10
electron, and 12 neutrons?
A 12
C20
D. 32
Answer:The mass numbr is 22
Explanation:
Mass number=number of protons+ number of neutrons....which is 10+12=22
When water vapor is cooled, it re-forms into water droplets. Why does this represent a conservation in mass?
50 POINTS!!!
Answer:
People, especially kids, tend to think that when water evaporates it just disappears, or turns into the air. But we know based on the law of conservation of mass that any time water changes state it keeps the same mass!
Similarly, when water vapor turns to water droplets, when it goes from its gas to its liquid state, it still has the same mass. It's just in a different phase. This is a perfect example of conservation in mass!
A blacksmith making a tool heats 525 grams of steel to 1230°C. After hammering the steel, she places it into a bucket of water to cool it. When
she removes the steel from the water, it's at 50°C. How much heat does the steel release if its specific heat capacity is 0.486 Joules/gram degree
Celslus?
A. 301,000 Joules
B. 12,800 Joules
C. 1,270 joules
D. 241 Joules
E. 4.62 joules
The heat energy released here can be determines using calorimetric equation. The heat energy released by the steel is 301077 J. Hence, option A is correct.
What is calorimetry ?Calorimetry is an analytical technique used to determine the heat energy absorbed or released by a system. The calorimetric equation connecting the heat energy with the mass m, specific heat capacity of the substance c and the temperature difference ΔT is given below:
q = m c ΔT.
given ,
mass of the steel m = 1230 °C
c for steel = 0.486 J/g °C
ΔT = 1230 - 50 °C = 1180 °C.
Then, the heat energy released by the steel into water is determined as follows:
q = 1180 °C × 525 g × 0.486 J/g °C
= 301077 J.
Therefore, the heat energy released by the steel is 301077 J.
Find more on calorimetry:
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Which hydrocarbon is saturated?
1. C2H2
2)C3H4
3)C4H6
4)C4H10
Answer: 4, c4h10
Explanation: source:
C4H10 is a saturated hydrocarbon.
What is a hydrocarbon?A hydrocarbon is an organic compound which consists of carbon (C) and hydrogen (H). For example, C4H10, C2H2 etc. There are four types of hydrocarbons namely alkanes, alkenes, alkynes and aromatic hydrocarbons.
What is a saturated hydrocarbon?A saturated hydrocarbon is that hydrocarbon in which the carbon atoms are linked only by single bonds. For eg: CH4, C2H6 etc. All alkanes are saturated hydrocarbons.
An unsaturated hydrocarbon is that hydrocarbon in which the carbon atoms are linked through double or triple bonds. For eg: C2H2, C3H4 etc. Alkenes and alkynes are unsaturated hydrocarbons.
C2H2, C3H4 and C4H10 are all unsaturated hydrocarbons. C4H10 is a saturated hydrocarbon as all the carbons are linked through single bonds.
Hence, D is the correct option.
To learn more about hydrocarbons here
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2. Explain why carbon dioxide in the atmosphere is increasing.
3. Describe one explanation for why Earth’s climate is becoming warmer.
4. Analyze the factors that have limited the effectiveness of the Kyoto Protocol.
Answer: Carbon dioxide concentrations are rising mostly because of the fossil fuels that people are burning for energy.
(1)Extra greenhouse gases in our atmosphere are the main reason that Earth is getting warmer.
(2)Greenhouse gases, such as carbon dioxide (CO2) and methane, trap the Sun's heat in Earth's atmosphere.
(3)It says that the 1997 Kyoto Protocol was an unmitigated success, with every single one of the 36 countries that signed up reducing their mean annual greenhouse gas emissions from 2008-2012 by an average of 5% relative to the levels seen in 1990.Jun 15, 2016 Many argue that Kyoto's failure is due to deficiencies in the structure of the agreement, such as the exemption of developing countries from reductions requirements, or the lack of an effective emissions trading scheme.by 2012
Explanation:
Consider the nuclear equation below. Superscript 235 subscript 92 upper U right arrow superscript 4 subscript 2 upper H e. What is the nuclide symbol of X? Superscript 231 subscript 94 upper P u. Superscript 235 subscript 90 upper T h. Superscript 239 subscript 94 upper P u. Superscript 231 subscript 90 upper T h.
Answer:
[tex]\rm_{90}^{231}\text{Th}[/tex]
Explanation:
The unbalanced nuclear equation is
[tex]\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} + X[/tex]
Let's write X as a nuclear symbol.
[tex]\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} + _{Z}^{A}\text{X}[/tex]
The main point to remember in balancing nuclear equations is that the sums of the superscripts and of the subscripts must be the same on each side of the reaction arrow.
Then
235 = 4 + A , so A = 235 - 4 = 231, and
92 = 2 + Z , so Z = 92 - 2 = 90
And your nuclear equation becomes
[tex]\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} +\, _{90}^{231}\text{X}[/tex]
Element 90 is thorium, so
[tex]\rm X = _{90}^{231}\text{Th}[/tex]
Answer:
its d
Explanation:
edg
indicators are chemicals that change colour in presence of an acid or an alkali. Universal indicators and pH meters are used to measure pH. Desccribe how you would use a universal indicator to find the pH of sodium hydroxide. What colour change would you observe
Answer:
Purple. Sodium Hydroxide is an Alkali/base. Bases and Alkalis
have a pH greater than 7, and turn blue-purple in universal
indicator.
Explanation:
Where are most insect eggs laid on a corpse? *
A)On the head only.
B)Under the corpse.
C)Only on exposed skin
D)Body openings/wounds
Answer: usually D (but it could also be C)
Explanation:
what tool do you have to use to find exactly 15.7 milliliters of vinegar? A beaker B balance C meter stick D thermometer E stopwatch F graduated cylinder
Answer:
A Graduated Cylinder would be you answer because they have markings for smaller measurnments like milliliters
Explanation:
Grains of sugar dissolve more quickly in tea than do sugar cubes. Which answer correctly describes why this occurs?
The sugar grains form a saturated solution.
The sugar cube is already at equilibrium.
The sugar grains have a greater surface area.
The sugar cube is at great pressure.
Answer:
sugar cube is at great pressure
Explanation:
this is because great pressure means its more solid
How many neutrons does the isotope N-14 have? 6 7 8 9
Answer:
7
Explanation:
An isotope is an atom that has a different number of neutrons than the standard for that atom.
1)Nitogen -14 has 7 protons in the nucleus for its an isotope of nitrogen which has an atomic number of 7.
2)Now we need to find the number of neutrons. This is implied in the name of the isotope whereby the protons and neutrons add up to its atomic number. So
(14-7 protons= 7 neutrons.)
So it has 7 neutrons.
7
I just did it on edgen :)
2. Which ecoregions are most likely to experience a drought or heatwave?
a. West Texas Ecoregions
b. Central Texas & Panhandle Ecoregions
c East Texas Ecoregions
d. Coastal Ecoregions
Answer: A--- West Texas Ecoregions.
Explanation:
The West Texas Eco regions are high plains characterized with dry flat land which receives lowest amount of rainfall thereby having very short grass vegetation. this flat land has a leveled plateau which ranges from about 3000 to 4500 ft and receives the highest winds due to its nature.
Because It is a dry region, it is prone to heatwaves and drought.
HELP ME!!ILL GIVE U BRAINLIESTT!!!!!
8 points
11. Humans have negatively impacted the environment for
years. Which
events represent ways humans have harmed the environment. (Choose all
that apply.)
burning fossil fuels
minning
planting trees
using solar power
using fertilizers
recycling
(There’s more than one answer btw)
Answer:
Burning Fossil Fuels
Mining
Using Fertilizers
PLEASEEEEEEE HELPPPPPPPPPP I BEGGGGG FOR HELPPPPPPP
How many formula units are in a sample of salt, NaCl, with a mass of 87.75 grams?
Answer:
Number of Nacl units in mass of [tex]87.75[/tex] grams [tex]= 1.50[/tex]
Explanation:
Mass of one unit of NaCl or one atom of NaCl is [tex]58.44[/tex] g/mol
The total mass of the NaCl is [tex]87.75[/tex] grams.
The number of unit in [tex]87.75[/tex] grams of NaCl is equal to [tex]87.75[/tex] grams divided by mass of one unit of NaCl i.e [tex]58.44[/tex] g/mol
This can be mathematically be presented as
[tex]\frac{87.75}{58.44} \\[/tex] Units
[tex]1.50[/tex] Units
Number of Nacl units in mass of [tex]87.75[/tex] grams [tex]= 1.50[/tex]