Answer:
first answer
Explanation:
In an experiment, how many variables should you change at a time? And why?
Answer:
it should test one variable at a time.
Explanation: because you will not be able to tell which variable is responsible for the observed results.
how many grams of hydrogen gas are needed to react with 688 grams of oxygen to make water? (3 sig figs)
Answer:
86 g H₂
Explanation:
The reaction between hydrogen gas (H₂) and oxygen gas (O₂) to produce water (H₂O) is described by the following balanced chemical equation:
2 H₂(g) + O₂(g) → 2 H₂O(g)
As we can see, 2 moles of H₂ reacts with 1 mol of O₂. We have to convert the moles to mass by using the molar mass (MM) of each compound:
MM(H₂) = 1 g/mol x 2 = 2 g/mol
2 moles H₂ = 2 mol x 2 g/mol = 4 g
MM(O₂) = 16 g/mol x 2 = 32 g/mol
1 mol O₂ = 1 mol x 32 g/mol = 32 g
Thus, 4 grams of H₂ reacts with 32 g of O₂. The stoichiometric ratio H₂/O₂ is 4 g H₂/32 g O₂. So, we multiply the stoichiometric ratio by the mass of O₂ we have (688 g) to calculate the grams of H₂ we need:
4 g H₂/32 g O₂ x 688 g O₂ = 86 g H₂
A structure that contains a watery fluid which protects the embryo/fetus is 7 7 point
known as? *
chorion
amnion sac
uterus
cervix
Answer:
and unborn baby
Explanation:
an unborn baby
Why are stars special sources of light?(2 points)
They are made of gas.
O They twinkle in the night sky.
They get their light from the sun.
They give off their own light energy.
Answer:
They give off their own light energy
Explanation:
I'm taking astronomy and I answered this questions not too long ago
Which properties describe the elements in group 18?
Please help I’ll even give you brainliet
What is the molecular formula for a compound that is 34.31% sodium, 17.93% carbon, 47.76% oxygen and has a molar mass of 134.00g?
Answer: Na2C2O4 probably sodium oxalate
Explanation: assume you have 100 g substance.
Mass of Na is m(Na) = 34.31 g, m(C) = 17.93 g and m(O) = 47.76 g.
Calculate moles n(Na) = 34.31 g/22.99 g/mol= 1.49 mol.
For C n(C) = 1.49 mol and n(O) = 2.985. You divide all by 1.49 you
Get n(Na) : n(C) : n(O) = 1:1:2 M(NaCO2) = 67 g/mol.
Divide 134:67 = 2. You get formula Na2C2O4
And this one too please
Answer: Groups 15 and 16.
Explanation:
All other answer choices include metals, which form ionic bonds.
Which kind of wind is most likely responsible for the movement of this
weather system from Dallas to St. Louis and then to Pittsburgh?
A. Southern polar easterlig
B. Westerlies
C. Northern polar easterlies
D. Trade winds
SUBMIT
Answer: Westerlies
Explanation:
Answer:
B. Westerlies
Explanation:
I got ir right
kinetic energy???
short version please
Answer:
Kinetic energy, form of energy that an object or a particle has by reason of its motion.
Explanation:
a shorter one
Answer:
is the energy of a body due to its motion pls mark me us briansit it means lot to me follow for more answer
In order to form water, two hydrogen atoms and one oxygen atom must be
A. dissolved.
B. bonded.
C. divided.
D. mixed.
Answer:
B bonded
Explanation:
Two molecules of hydrogen gas (two hydrogens bonded together) are combined with one molecule of oxygen gas (two oxygen atoms bonded together) in order to form two molecules of water (two hydrogen atoms bonded to one oxygen atom). What are covalent bonds? Covalent bonds occur when two or more atoms share electrons.
In order to form water, two hydrogen atoms and one oxygen atom must be bonded. The correct option is B.
What are covalent bonds?Covalent bonds between two or more atoms occur when they share electrons. with each other.
Two molecules of hydrogen gas are combined with one molecule of oxygen gas which forms two molecules of water. Hydrogen take one electron and oxygen can donate two electrons. One oxygen shares two electron with two hydrogen with one electron gaining capacity.
Thus, in order to form water, two hydrogen atoms and one oxygen atom must be bonded. The correct option is B.
Learn more about covalent bond.
https://brainly.com/question/10777799
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Calculate the number of atoms in 0.50 moles of Barium
i need help again guyss
Find a room that can be made completely dark. In the room, tape the pieces of construction paper on a wall, slightly above eye level. Turn on the flashlight, and turn off the lights in the room. Hold the flashlight over your head and angle it down slightly so the light hits the colored paper. Can you see the light traveling through the room before it hits the paper?
Answer:
Yes, I can see the light traveling through the room before it hits the paper.
Explanation:
edmentum
Since light rays travels in a straight line, the light traveling through the dark room can be seen before it hits the paper.
What are light rays?Light rays refers to a straight line path through which light waves travel.
Light rays travel in a straight line and this phenomenon is known as the rectilinear propagation of light.
In a dark room, the path of light rays travelling in a straight can be seen.
Therefore, the light rays traveling through the room can be seen before it hits the paper.
Learn more about light rays at: https://brainly.com/question/478185
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ANYONE HELP MEE!! ASAP!
Answer:
The energy of the molecules in the apple decreased.
Explanation:
A.
What drives the flow of energy in cycling of matter in the atmosphere
does a single atom make a difference to the properties of matter?
Yes, all things are made of atoms, and all atoms are made of the same three basic particles - protons, neutrons, and electrons. But, all atoms are not the same. ... The difference in the number of protons and neutrons in atoms account for many of the different properties of elements.
BaCl² produces barium gas plus chlorine gas when heated. what would be the combined mass of the barium and chlorine if 15 g of Barium chloride was heated
When Na2O is mixed with Mn(NO3)4 it forms NaNO3 and MnO2. We start with 25.0 g
of sodium oxide and 56.1 g of manganese (IV) nitrate.
How many grams of sodium nitrate can be produced?
Need done fast please! 41 points
Heat energy provided during phase change is used to:
increase kinetic energy
break intermolecular bonds
break intramolecular bond
decrease kinetic energy
Answer:
I'm not exactly sure but I think it's the first one if I'm wrong tell me so I know and I don't know how I can get points back but if I can figure it out I will tell me if I'm wrong
If you try to place the compound on the pan over the flame, what could possibly happen? Explain your answer. [2 marks] anyone please help me!!:(
Answer:
it will probably flame up or explode or maybe start boiling
Obtaining crude oil for refining is an example of
A. Constructive occupation
B. Extractive occupation
C. Manufacturing occupation
D. Tertiary occupation
E. Service occupation
Answer:
B: extractive occupation
2. Have you ever seen a natural event that surprised
you? Why was it surprising?
Answer:
I have seen many lightning storms before. However, one of the most surprising ones was when I was at my house. It was around midnight when I awoke from the sound of lightning in the distance. I was also half awake so this could be another reason this was the most surprising, but lightning struck near my area. i could see the light through my curtains and the sound was loud enough to awake everyone in my house, even the deep sleepers. I practically jumped out of bed.
Which statement best describes the polarity of the molecule Sil4?
Answer:
I dont a picture
Explanation:
but the answer is 24
If 0.25 moles of KBr is dissolved in 0.5 liters of
heavy water which has a mass of 1,100 grams
per liter, what is the concentration?
Answer in units of m (molal).
Answer:
[KBr] = 454.5 m
Explanation:
m is a sort of concentration that indicates the moles of solute which are contianed in 1kg of solvent.
In this case, the moles of solute are 0.25 moles.
Let's determine the mass of solvent in kg.
Density of heavy water, solvent, is 1.1 g/L and our volume is 0.5L.
1.1 g = mass of solvent / 0.5L, according to density.
mass of solvent = 0.5L . 1.1g/L = 0.55 g
We convert the mass to kg → 0.55 g . 1kg /1000g = 5.5×10⁻⁴ kg
m = mol/kg → 0.25 mol /5.5×10⁻⁴ kg = 454.5 m
When an atom loses an electron, the resulting charge on the atom is ____
Answer:
Positive
Explanation:
The atom will gain a positive charge by losing an electron
Answer:
cation
Explanation:
1.0 mole of KCl(aq) is added to which solution to produce a precipitate?
A)
Lit
B)
Ca2+
Agt
D)
Zn2+
Answer:
Ag+
Explanation:
If you imagine as if the problem were double replacement, you would pair the Cl with one of the following ions provided in the choices. As seen on Table F, Ag+ paired with Cl- produces an insoluble compound, hence the precipitate. All the other ions shown in the multiple choice section, when paired with Cl- will produce a soluble compound, as a result NOT a precipitate.
I just got confessed to
but i only like the person 89% out of 100...
what should I do ?
Answer:
:)haha
Explanation:
Answer:
:D
Explanation:
1 poin
2) Iron is found in the Earth as iron
oxide (Fe203). Iron oxide is reduced
to produce iron. Balance the equation
for the reaction: ...Fe2O3 + ..... →
.....Fe + .....CO2
Your answer
duehrneidudbeneisubebekeidbdbbe
help me with this pleasee
Choose the correct option
Answer:
C
Explanation:
Hope this helps.