Potassium cyanide is a toxic substance, and the median lethal dose depends on the mass of the person or animal that ingests it. The median lethal dose of KCN for a person weighing 215 lb (97.5 kg ) is 8.84×10−3 mol .
What volume of a 0.0250 M KCN solution contains 8.84×10−3 mol of KCN?
Express the volume to three significant figures and include the appropriate units.
Answer:
0.354L
Explanation:
Given parameters:
Molarity of KCN = 0.025M
Number of moles = 8.84 x 10⁻³mol
Unknown:
Volume of KCN = ?
Solution:
The molarity of a substance is expressed as;
Molarity = [tex]\frac{number of moles }{volume }[/tex]
Volume of KCN = [tex]\frac{number of moles }{molarity}[/tex]
Now insert the parameters and solve;
Volume of KCN = [tex]\frac{0.00884}{0.025}[/tex] = 0.354L
Which element below would you most likely expect to be a poor conductor of heat and electricity?
Answer:Nonmetals and rubber
Explanation: hope this helps
Answer:
phosphorus
Explanation:
non-metals are poor conductors
What is the mass of one electron in grams if an electron has the charge of
-1.6022 x 10-19C and lg = -1.76 x 108 C.
The mass of one electron : 9.103 x 10⁻²⁸ g
Further explanationElectrons are a part of the atomic nucleus particles (including protons and neutrons), and are negatively charged (-1)
An electron has the charge of -1.6022 x 10⁻¹⁹C
1 g = -1.76 x 10⁸ C
so the mass of one electron :
[tex]\tt \dfrac{1.6022\times 10^{-19}}{1.76\times 10^8}=9.103\times 10^{-28}~g[/tex]
3x - 12 = 7x + 8
-4x - 12 = 8
-4x - 20
X = -5
Answer:
1.Set your equations Raquel to each other
2.given
3.subtract 7x from both sides
4. Add 12 to both sides
5.divide both sides by four and you get negative 5
Explanation:
Give the applications of EMF measurement
Answer: Determination of Equilibrium Constant, Determination of Solubility Products, Determination of pH, Determination of Activity Coefficients,
Explanation:
Predict the products for the following chemical reaction: H2 + O2 →
a. H30
b. H20
c. H2OH
d. OH + OH
O a
A 75.0 gram sample of water at 25.0 degrees Celsius is mixed with a 100. Gram sample of water at 60.0 degrees Celsius. What is the final temperature of the water?
Answer:
The final temperature of the water = 45°C
Explanation:
Heat lost = heat gained
Heat lost by water at 60°C = m₁CΔT₁
Heat gained by water at 25°C = m₂CΔT₂
where m₁ is mass of water at 60°C = 100.0 g; m₂ is mass of water at 25°C = 75.0 g
C, specific heat capacity of water = 4.18 J/g°C
ΔT₁ = (60 - T); ΔT₂ = (T - 25); T = final temperature of the water
m₁CΔT₁ = m₂CΔT₂
100 * C * (60 - T) = 75 * C * (T - 25)
-100T + 6000 = 75T - 1875
-(100T + 75T) = -(6000 + 1875)
175T = 7875
T = 45°C
Therefore, final temperature of the water = 45°C
What is happening in this picture?
Answer:
in first picture pressure is low and in second picture the pressure is high
2ans in first picture air is
less amount
in second picture air is high amount
How many moles are in 68 grams of copper (II) hydroxide, Cu(OH)2
heres your answer mate...
The ghost plant is white with a single stalk. Even though it looks more like a mushroom, the ghost plant is related to blueberry plants. The ghost plant is a parasite that feeds on fungi under the ground. Ghost plant cells have all the usual plant organelles except for a .
Answer:
chloroplast
Explanation:
A student is attempting to identify an unknown liquid. She places 10 mL of the liquid in a test tube and begins heating it over a burner. She checks and records the temp every minute until it begins to boil. What is the independent variable?
Answer:
The time of heating
Explanation:
Let us analyse the experiment closely; the temperature of the liquid increases as the time of heating increases. This implies that the temperature of the liquid is dependent on the time of heating of the liquid. The longer the time of heating, the greater the increase in temperature until the boiling temperature is eventually attained.
Hence, the temperature of the liquid is the dependent variable, the time of heating is the independent variable when the heating rate is held constant.
what is the soul of water?
Answer:
soul eater is a social enterprise
Explanation:
they donate a minimum of 10 percent to the soul community . soul water was born from the idea that everyone should be able to enjoy quality drinking tap water
In the future, what would you expect to happen to the distances between galaxies?
The distances between galaxies are expected to increase.
This is due to the endless expansion of the universe, proposed by cosmological inflation.
For this reaction, C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O, the ∆H is –2200 kJ. If two moles of C3H8(g) reacted with excess oxygen, what would be true?
A) 4400 kj of heat released into surroundings
B) 4400 kj of heat absorbed by system
C) 1100 kJ heat released into surroundings
D) 1100 kJ heat absorbed by system
A) 4400 kj of heat released into surroundings
Further explanationReaction
C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O, the ∆H is –2200 kJ
Reaction exothermic( ∆H=-, released heat to surrounding) and for combustion of 1 mole of C3H8
So for two moles of C3H8, the enthalpy :
[tex]\tt -2200\times 2=-4400~kJ[/tex]
Determine which equations you would use to solve the following problem: Calculate the amount of heat needed to change 20.0 g of ice at -10.0°C to water at 89.0°C.
Answer:
Q = 4019.4 J
Explanation:
Given data:
Mass of ice = 20.0 g
Initial temperature = -10°C
Final temperature = 89.0°C
Amount of heat required = ?
Solution:
specific heat capacity of ice is 2.03 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 89.0°C - (-10°C)
ΔT = 99°C
Q = 20.0 g ×2.03 J/g.°C × 99°C
Q = 4019.4 J
Sea-Floor Spreading1. The arrows on the figure show the ocean floor spreading from the ridge. What are three kinds of evidence scientists have found to support this idea?
A. B. C.
I NEED HELP
URGENT PLEASE HELP NOW!!
When do most ionic bonds form, based on this Periodic Table?
when elements from B bond with themselves
when elements from A bond with elements from B
when elements from C bond with elements from D
when elements from A bond with themselves
Answer:
when elements from A bond with elements from B
Explanation:
The elements in part A are metals and that of B are non-metals. Ionic bonds are formed between metals and non-metals. Thus option b is correct.
What is ionic bonding?An ionic bond is formed between a metal and non-metal through loss of electron from the metal to the non-metal. Metals are electron rich and easily loss electrons.
Non-metals are electronegative and they are electron -deficient. They need to gain electrons to attain stability. Therefore non-metals such as oxygen, nitrogen, carbon etc. bonds with metals by gaining electrons from metals.
The positive charge of metal acquired by loss of electron and negative charge of nonmetals acquired by gain of electron attracts electrostatically and form the ionic bond.
The elements from A thus bonds ionically with elements from B.
To find more on ionic bonding, refer here:
https://brainly.com/question/11527546
#SPJ2
oxygen - 17
Atomic #
Atomic mass
# of protons
# of neutrons
# of electrons
Answer:
atomic #8
atomic mass 15.999U
# protons 8
# neutrons 8
# protons 8
do you agree or not that evidence is only used to back scientific laws and provide evidence why or why not!!!!!! thank you, will mark brainliest to whoever does it correct the 1st time what i asked!!!!!!!!!!
Answer:
yes, because evidence from scientifically research studies, is important because it lets us make decisions based on what works with studies of science we can know if this is right or not
Explanation:
Hope i helped~
4-How does the concentration of ions in a strong acid differ from a weak acid?
The temperature T in Kelvin is 273.15 more than temperature C in degrees Celsius. Use your function to find the equivalent temperature in Kelvin for 100*C.
Answer:
T(K) = 373.15 K
Explanation:
The kelvin is the base unit of temperature in the International System of Units (SI). The symbol used to express temperature in kelvins is K.
The temperature of zero kelvins is called the absolute zero. It is considered to be the lowest possible temperature, although nothing has reached it. The absolute zero (0K) is - 273.15 degrees Celsius.
This is the equation we can use to solve this question:
[tex]T(K) = T(C) + 273.15[/tex]
We have 100*C.
[tex]T(C) = 100 C[/tex]
[tex]T(K) = 100C + 273.15[/tex]
[tex]T(K) = 373.15 K[/tex]
The diagram shows a transform fault. What is a likely result of slippage along
this fault?
Fault
O.
A. Pyroclastic flow
B. Shield volcano
C. Earthquake
D. Crater
Answer:
C. Earthquake
Explanation:
Earthquake is a likely result of the slippage along this fault boundary.
At a transform margin, rocks are moving parallel to one another. This often causes a slippage that leads to the generation of earthquakes.
An earthquake is a sudden displacement within the earth that leads to a sudden release of energy in all direction. The slippage on the surface of a transform fault often lead to earthquakes.Answer:
C
Explanation:
When determining an element’s chemical properties, the most important subatomic particle to look at is
Answer:
Electrons
Explanation:
When determining the chemical properties of elements, the most important subatomic particle to consider is the electrons.
Electrons are negatively charged particles that orbits an atom. They occupy the extranuclear space of an atom.
These electrons determines the chemical properties of each atom. Most especially, the valence ones. All elements wants to resemble the noble gases, so they alter their number of electrons in order to attain this stable state.
If 100 yards = 1 football field, what is the length, in meters, of 4.9
football fields?
if your mass was 200 grams what would your weight be on this planet.
Answer:
200
Explanation:
Explanation:
take your weight times by the amount of newtons in a pound, which is 4.45
then convert newtons into grams.
Which of the following would be considered a derived unit? A) length B mass C) density D) temperature
Answer:
density because it S.I unit is derived from fundamentals
How can we predict melting points?
Explanation:
Many of the properties of organic molecules can be predicted based on the strength of their cohesive molecule-molecule interactions (i.e. how much the molecules want to stick together). The boiling point (BP) and melting point (MP) of an organic molecule is related to: 1) the molecular weight of the molecule and 2) the "stickiness" of individual molecules for their neighbors.
For example, molecules in a liquid are held together by attractive interactions between molecules. These interactions must be broken (by adding heat) in order to transition into the gas. The stronger the cohesive interactions, the more heat that is necessary for the liquid-to-gas phase transition. These same attractive molecule-molecule interactions have to be broken for a solid to liquid phase change.
Examples: (Rank the following molecules in terms of MP and BP.)
Introduction to intermolecular forces:
All of the attractive intermolecular forces are based on the electrostatic attraction of positive charges on one molecule with negative changes. The stronger the charges, the stronger the attraction between molecules.
How to:
In general, comparisons can only be made between molecules with similar formulas or molecular weights.* First, identify the functional groups in the molecules being compared. Each functional group can form different types of intermolecular interactions (see the chart above). Interactions higher up on the chart form stronger cohesive interactions and will have higher boiling points and melting points.
* Note that larger molecules usually have higher boiling points and melting points. This is not because of their higher molecular weights but because they usually have greater surface areas with which to form more intermolecular interactions. This is also why linear molecules tend to have higher MPs and BPs than branched (or more spherically shaped) molecules. Linear molecules will have more surface area than a more spherically shaped molecule.
All three molecules have approximately the same molecular formula and molecular weights. Only molecule A contains a strongly polarized or ionic functional group: an aldehyde. The C=O group in aldehydes generate a strong molecular dipole (partial + and - charges). Thus, it can form weak attractive dipole-dipole interactions, and A will have the highest boiling point and highest melting point in this series of compounds.
Molecules B and C are alkanes. They can only form the weakest attractive dispersion interactions between their molecular surfaces. Due to its long-thin shape, B will have a greater surface area and can form more dispersion interactions than the rounder C. Therefore, B will have a higher boiling point and melting point than C.
Molecule A is ionic (it has charges). Therefore, it can form the strongest ion-ion interactions and will have the highest boiling point and melting point.
Molecule B is a carboxylic acid with an acidic proton and basic lone pairs. Therefore, it can form medium strength hydrogen bonding interactions, and it will have the next highest boiling point and melting point.
Molecule C is a carboxylic ester, which is a polar functional group. However, it does not have an acidic proton. Therefore, esters cannot form hydrogen bonds with themselves. Instead, they can only form weak dipole-dipole interactions and will have the lowest boiling point and melting point in this series of compounds.
Answer:
Explanation:
By thinking about non covalent intermolecular interactions, we can also predict relative melting points. All of the same principles apply: stronger intermolecular interactions result in a higher melting point.
What is arcade in south Center
Answer: game stop and mind games
Explanation:
i live near there
Magnesium (24.30 g) reacts with hydrogen chloride (X g) to produce hydrogen gas (2.04 g) and magnesium chloride (96.90 g). How much hydrogen chloride was used in the reaction?
Answer:
[tex]74.64\ \text{g}[/tex]
Explanation:
Reactants
Magnesium = 24.3 g
Hydrogen chloride= x g
Products
Hydrogen gas = 2.04 g
Magnesium chloride = 96.9 g
As the mass of the reactions is conserved we have
Mass of reactants = Mass of products
[tex]24.3+x=2.04+96.9\\\Rightarrow x=2.04+96.9-24.3\\\Rightarrow x=74.64\ \text{g}[/tex]
Mass of hydrogen chloride is [tex]74.64\ \text{g}[/tex].
How much heat is absorbed when 15.0 g of liquid water is
heated until the temperature increases by 6.0°C? The specific
heat of liquid water is 4.18 J/gºC.
Answer:
376.56
Explanation:
using the formula q=mcΔT, where m=15g, C=4.18J/g°C and ΔT=6.0°C