the empirical chemical formula of X is CH4
Explanation:Step 1: Imagine you have a sample of compound weighing exactly . Multiply the mass of this sample by the mass percents to find the mass of each element in the sample
Step 2: Divide the mass of each element by the element's molar mass to find the moles of each element in the sample. Remember to round your answers to the correct number of significant digits.
Step 3: Divide the moles of each element by the the smallest number of moles of any element to find the mole ratio of elements in the sample.
Step 4: Multiply the mole ratio by the smallest whole number that changes it into a whole number ratio to find the atom ratio of elements in the sample.
Note that the result of each multiplication must equal a whole number only within measurement uncertainty.
The measurement uncertainty in this calculation comes from the measurement uncertainty of the mass percents given in the question. The mass percents each have significant digits. That means each mass percent has some measurement uncertainty in the third significant digit, and only the first two significant digits can be considered completely reliable.
In Step 1 you multiplied each mass percent by something with zero uncertainty (the exactly you assumed your sample weighed), in Step 2 you divided by a measurement with more than significant digits (the molar mass of the elements), and in Step 3 you divided by a measurement with the same number of significant digits (the least number of moles of any element in the compound). None of these steps added to the measurement uncertainty of your calculation.
Therefore, the measurement uncertainty in the final result of all your calculations is determined by the measurement uncertainty in the original mass percents and will be in the third significant digit. That means the result of each of the final multiplication steps must equal a whole number only to within the first two significant digits.
The whole numbers in the last column of the table are and .
Which hypothesis is directly tested in an experiment?
a. One specific confounding variable hypothesis.
b. All of the confounding variables hypotheses.
c. The research hypothesis.
d. both b and c
If a metal that had reacted very
slowly with dilute acid was
tested with a concentrated
one, what would you predict
would happen?
Answer:
It would react better than what with dilute and will furnish more hydrogen gas.
When you push or pull something, you are creating
force but could be tension
How many molecules are in 1 mole of molecules?
Answer:
6.022x10^23
Explanation:
Can someone please help I need help?!?!
Answer:
a: 6 moles
b: 6.75 moles
c: 5 grams
Explanation:
a: mole ratio 2:3
b: mole ratio 2:3
c: mole ratio 2:2
Help me please
Answer & exp.
Explanation:
Some Rules Regarding Oxidation Numbers:
- Hydrogen has oxidation number of + 1 except in hydrides where it is -1
- Oxygen has oxidation number of -2 except in peroxides where it is -1
- Some elements have fixed oxidation numbers. E.g Halogen group elements has oxidation number of -1
- Oxidation number of a compound is the sum total of the individual elements and a neutral compound has oxidation number of 0.
A. HI
Hydrogen has oxidation of + 1
Oxidation number of I:
1 + x = 0
x = -1
B. PBr3
Br has oxidation number of - 1
Oxidation number of Pb:
x + 3 (-1) = 0
x = + 3
C. KH
Hydrogen has oxidation of + 1
Oxidation number of K:
1 + x = 0
x = -1
D. H3PO4
Hydrogen has oxidation number of + 1
Oxygen has oxidation number of -2
Oxidation number of P:
3(1) + x + 4(-2) = 0
3 + x - 8 =0
x = 5
Does anyone knows how to solve this??
Answer:
²⁴³₉₅Am --> ²³⁹₉₃Np + ⁴₂He
Explanation:
In alpha decay;
The mass number decreases by 4
Atomic Number decreases by 2
Mass Number = 243 - 4 = 239
Atomic Number = 95 - 2 =93
Element = Neptunium (Np)
Equation for the decay is given as;
²⁴³₉₅Am --> ²³⁹₉₃Np + ⁴₂He
Hi hello I need help ASAP
Determine the slope of this line
a.2.5
b.0.75
c.1
d.0.4
Answer:
so I got it wrong the first time but you should pick two points on the line such as 4,3 and 9,5. Then use the equation y^2 - y^1/ x^2 - X^1. You would get 2/5 which is D.
Explanation
How many moles are there 75.56 grams of KHCO3
Explanation:
mole = mass/molar mass
molar mass of KHCO3 = K + H + C + O3
39 + 1 + 12 + 3(16)
= 100g/mol
mass = 75.56
mole = 75.56/100
= 0.7556mol
Name two sources of cholesterol in the human body
Answer:
The cholesterol in your blood comes from two sources: the foods you eat and your liver. Your liver makes all the cholesterol your body needs.
plz help fast! P.S. I put chemistry by accident its biology lol
The measure of water’s ability of flow through sediment and rock is called
Answer:
Permeability.
Explanation:
The ability of a rock or soil to allow water to flow through it is call permeability. Materials such as gravel that allow the flow of water are permeable. Materials such as clay or granite that do not allow the flow of water are impermeable.
(Help would be greatly appreciated) Which sweet tea would you expect to taste the sweetest?
1. 1M
2. 3M
3. 3.1M
4. 2.5M
Answer:
3.1 M
Explanation:
3.1 M has the highest concentration of sweet tea so it should taste the sweetest.
Cart A has a mass of 24 kg and is being pulled with a force of 32 N. Cart B has a mass of
27 kg and is being pulled with a force of 33 N. Which cart will have the faster acceleration?
Mix 200 g of copper at 100 °C with 1,000 g of water at 20 °C. Final temp. = 21.42°C a) How much heat energy (q) did the water gain? b) Now solve for the specific heat (c) of copper:
Answer:
a) [tex]Q_w=5941.3J[/tex]
b) [tex]C_{Cu}=0.378\frac{J}{g\°C}[/tex]
Explanation:
Hello there!
In this case, when a hot substance is mixed with a cold one, we can evidence how the hot one is able to heat up the cold one as it cools down. Thus, the net heat flow for this problem can be set up as shown below:
[tex]Q_{Cu}+Q_{w}=0[/tex]
Whereas the heats can be written in terms of mass, specific heat and temperatures:
[tex]m_{Cu}C_{Cu}(T_F-T_{Cu})+m_{w}C_{w}(T_F-T_{w})=0[/tex]
Thus, we proceed as follows:
a. Here we compute Qw:
[tex]Q_w=1,000g*4.184\frac{J}{g\°C}(21.42\°C-20\°C) \\\\Q_w=5941.3J[/tex]
b. Now, since this heat is equal to the negative of the heat contribution of copper (as it cools down), we can compute the specific heat of copper as shown down below:
[tex]C_{Cu}=\frac{-5941.3J}{200g(21.42\°C-100\°C)} \\\\C_{Cu}=0.378\frac{J}{g\°C}[/tex]
Best regards!
I need help boys-girls
Answer:
1.) B
2.) water
An independent variable is
a.
directly changed by the experimenter.
b.
manipulated by changes to the dependent variable.
C.
a variable that is kept constant.
d.
a variable that is used as a control.
Answer:
a. directly changed by the experimenter.
Explanation:
In the case of mathematical modeling, analytical modeling , and experimental sciences, the number of dependent variables based upon the amount of independent variables.
The dependent variables represent the result or outcome whose changes is being determined.
An independent variable expressed in the name form like experimental or expected variable, is a variable i.e. created in an experiment in order to verify the effect on a dependent variable
Therefore the option a is correct
Which date has the longest daylight and the shortest darkness
The Winter Solstice.
A 1500 N force gives an object an acceleration of 3 m/s2.
What is the mass of the object?
Answer:
500kg.
Explanation:
Newton's Second Law relates force, mass and acceleration to one another through the equation:
F = ma
We can rearrange this equation algebraically to solve for mass:
m = F/a
Substituting our known values for the variables, we get:
m = 1500N/3m/s2
So mass of the object is 500kg.
We know it's kg because Newtons (N) are a unit defined as 1 kg/m/s2, so m/s2 cancels out when we divide :)
When a piece of copper metal at 100ºC was placed into a cup of water at 25ºC, the final temperature of both substances reached 30ºC within a minute. Which of the following statements is TRUE about the transfer of energy between the two substances?
A. Copper lost less energy than the amount of energy gained by water
B. Copper lost more energy than the amount of energy gained by water
C. Copper lost the same amount of energy that was gained by water
D. Copper gained the same amount of energy that was lost by water
Answer:
imma say C or D
Explanation:
Elements in a convolent bond are called ?
Answer:
A covalent bond is formed by an equal sharing of electrons from both the participating atoms. The pair of electrons participating in this type of bonding is called shared pair or bonding pair. The covalent bonds are also termed molecular bonds.
When you watch a sunset, is the Sun really moving across the sky? What's happening?
(Science)
A cube of steel with a mass of 150 grams is heated from 60°C to 150°C.
Use calorimetry to determine the amount of energy absorbed by the
metal. The specific heat capacity of steel is 0.466 J/g°C.
Answer:
1.
The energy lost by the water is given by:
where
m = 3.0 kg = 3000 g is the mass of water
Cs = 4.179 J/g•°C is the specific heat
is the change in temperature
Substituting,
2.
The energy added to the aluminium is given by:
where
m = 0.30 kg = 300 g is the mass of aluminium
Cs = 0.900 J/g•°C is the specific heat
is the change in temperature
Substituting,
4. 42.9 g
The mass of the water sample is given by
where
is the heat added
is the temperature change
Cs = 4.179 J/g•°C is the specific heat
5. 115.5 J
The heat used to heat the copper is given by:
where
m = 5.0 g is the mass of copper
Cs = 0.385 J/g•°C is the specific heat
is the change in temperature
6. 0.185 J/g•°C
The specific heat of iron is given by:
where
Q = -47 J is the heat released by the iron
m = 10.0 g is the mass of iron
is the change in temperature
Substituting,
Substituting,
Substituting,
Explanation:
Anyone help please more & you get extra points
Answer:
qns-4
1-multicellular organism
2-unicellular organism
3-unicellular organism
4-multicellular organism
5-unicellular organism
6-multicellular organism
7-unicellular organism
Al2(SO4)3 + 6 K --- > 3 K2SO4 + 2 Al
In an experiment, 46.8 grams of aluminum sulfate is reacted to make how many grams of potassium sulfate?
(8.6 1029) 7.4 X1029)
Answer:
65563.914234
Explanation:
8.61029 x 7.4 x 1029
63.716146 x 1029
multiply
= 65563.914234
Plants and animals require large amounts of water in order to survive. Although vast numbers of plants and animals have lived throughout time, the amount of water in our environment has remained relatively constant. Which of the following statements explains why this occurs?
A. Water continually flows from the center of Earth.
B. Vast quantities of water are created by lightning in clouds.
C. Organisms return water to the environment after they use it.
D. Organisms combine hydrogen and oxygen to make their own water.
please help me
Answer: C - Organisms return water to the environment after they use it.
Explanation: The amount of water on earth will always remain the same. Water goes in and out of all organisms. It is not possible to be more or less.
True or false: All molecules or atoms in a substance have the same amount of kinetic energy at a given temperature?
Answer:
false
Explanation:
Difference in neutrons in a molecule means that molecules have different masses. They will always have different energies
another example: water has less energy as a liquid than as a gas
I need help! Please & Thank you!
Answer:
I think it is B
Explanation:
The most valuable part of the carcass is the
Answer:
The rib and loin, because of their palatability and diversity in how they can be used--especially on the market.
Explanation:
Which is the Net Ionic Equation for:
(remember, the Net Ionic Eq. shows ALL of the PARTICIPANTS)
2FeCl3(aq) + 3Mg(s) ® 3MgCl2(aq) + 2Fe(s)
2Fe3+ (aq) + Cl3- (aq) + 3Mg(s) ® 3Mg3+ (aq) + Cl2- (aq) + 2Fe(s)
2Fe3+ (aq) + 6Cl- (aq) + 3Mg(s) ® 3Mg2+ (aq) + 6Cl- (aq) + 2Fe(s)
Answer: [tex]2Fe^{3+}(aq)+3Mg(s)\rightarrow 3Mg^{2+}(aq)+2Fe(s)[/tex]
Explanation:
Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and are present in an aqueous state and represented in the form of ions.
Net ionic equation : In the net ionic equations, we do not not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The complete balanced ionic equation will be:
[tex]2Fe^{3+}(aq)+6Cl^-(aq)+3Mg(s)\rightarrow 3Mg^{2+}(aq)+6Cl^-(aq)+2Fe(s)[/tex]
In this equation, [tex]Cl^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be:
[tex]2Fe^{3+}(aq)+3Mg(s)\rightarrow 3Mg^{2+}(aq)+2Fe(s)[/tex]