Answer:It allows us to see things so we know where we are going that’s why at night we had lamp posts
Explanation:
which phase does best describe the side of the moon that faces earth???
I WILL MARK BRAINLIEST THIS IS IMPORTANT
Answer:
Goes through cycles
Explanation:
Copy the sentences below. Correcting the five mistakes.
In a displacement reaction, a less reactive metal pushes out a more reactive metal from its compound. For example, iron displaces aluminium from aluminium oxide.
Answer:
In a displacement reaction, a more reactive metal pushes out a less reactive metal from its compound. For example, aluminium displaces iron from iron oxide.
Explanation:
Because aluminium is more reactive than iron, it displaces iron from iron(III) oxide. The aluminium removes oxygen from the iron(III) oxide: iron is reduced.
...
Hope this answer can help you. Have a nice day!
In a displacement reaction, a more reactive metal pushes out a less reactive metal from its compound. For example, aluminium displaces iron from iron oxide.
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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What mass of chromium would be produced from the reaction of 57.0 g of potassium with 199 g of chromium(II) bromide according to the following reaction? 2 K + CrBr2 2 KBr + Cr
Answer:
Mass of Chromium produced = 37.91 grams
Explanation:
2K + CrBr₂ → 2KBr + Cr
2mole 1 mole 1 mole
mass of Potassium = 57.0 grams
molar mass of Potassium = 39.1 g/mol
no of moles of Potassium = 57.0 / 39.1 = 1.458 moles
mass of CrBr₂= 199 grams
molar mass of CrBr₂ = 211.8 gram/mole
no of moles of CrBr₂ = 199 / 211.8 = 0.939 mole
From chemical equation
1 mole of CrBr₂ = 2 moles of K
∴ 0.939 moles of CrBr₂ = ?
⇒ 0.939 x 2/1 = 1.878 moles of K
1.878 moles of K is needed, but there is 1.458 moles of K. So, Potassium is completed first during the reaction . Hence, Potassium is limiting reagent. and CrBr₂ is excess reagent .
From chemical equation
2 moles of K = 1 mole of Cr
∴ 1.458 moles of K = ?
⇒ 1.458 x 1/ 2 = 0.729 moles of Cr
no of moles of Cr formed = 0.729 moles
molar mass of Cr = 52.0 g/mol
mass of one mole of Cr = 52.0 grams
mass of 0.729 moles of Cr = 52.0 x 0.729 = 37.908 grams
mass of Chromium produced = 37.91 grams
Which of the following is stored in the skeletal system?
A. potassium
B. calcium
phosphorous
D. sodium
Answer:
b calcium
Explanation:
Name the following straight-chain Alkanes (picture)
Answer:
I don't know about the rest but A is heptane
5. Which statement is NOT true?
a. Light travels with or without a medium.
b. Sound must have a medium to travel through.
c. Both light and sound must have a medium to travel through.
d. Light travels faster than sound.
Answer:
A: true.
B: true.
C: false
D: true.
Explanation:
Light is an electromagnetic wave which travels regardless of whether there is medium. sound is a wave disturbance in medium meaning it must have matter. Also light is much faster then sound.
In Humans, the liquid waste
filtered by the kidneys is stored
in the ......?
A) Stomach
B) Bladder
C) Lungs
D) I'm not sure. I need
more help with this
topic.
What is the mass of 3.00 moles of carbon
Answer:
36 grams as 1 mole is 12 grams
Answer:
tbh idk cause I will love to answer your question but ehh
Answer the questions using the drop-down menus.
Which is the independent variable in this experiment?
Which is the dependent variable in this experiment?
Which is a controlled variable in this experiment?
In the experiment to measure the heat absorbed by a material placed in
the Sun, we have;
The independent variable is either the angle of insulation or the type of materialThe dependent variable is the temperature of the materialThe controlled variable is the type of material when the angle of insulation is the independent variable and vice versaWhat differentiates the given experimental variables?The possible experiment is with regards to the factors that influence energy from the Sun
The factors investigated are;
The type of material and the angle of lighting (insulation) affects the absorption of heat
The independent variable is the variable that is the cause of the effect
measured in the experiment.
It is the variable that the researcher has control over or controls and
varies during the experiment to produce the measured effect.
In the above experiment, the independent variable are either ;
The angle of insulation or the type of material respectivelyThe dependent variable is the variable that is under test or that is being measured.
In the above experiment the dependent variable is the temperature of the material which can be measuredThe controlled variable is the variable that remains the same or is held
constant during the experiment and can be used as reference to
compare the dependent variable.
In the experiment, the controlled variable are either;
The type of material when the angle of insulation is the independent variable or vice versaLearn more about independent and dependent variables here:
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Answer:
angle of light
temperature of material
type of material
Explanation:
E d g e 22 !
PLEASE ANSWER ASAP- 2 MIN LEFT
A pH of 7 indicates that a solution is ___________ ; a ph <7 would mean the solution is ____________________; and a pH >7 is a(n) ---------- solution.
Answer:
neutral, acidic, basic
Explanation:
Know the acidity rules. Sorry I just saw this!
- Hope that helps! Please let me know if you need further explanation.
DNA is a nucleic acid made of building blocks called nucleotides.
Which of the following options make up nucleotides?
Answer:
Nucleotides are made up of a five carbon sugar such as ribose or deoxyribose and a group of phosphate with 1-3 phosphates
Answer:i don’t see any answer choices but i guess the nucleotides are A, T, C, and G?
Explanation:
Fill in the missing piece of the table
Answer: The final volume [tex]V_2[/tex] is 263.09 ml
Explanation:
To calculate the final volume of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
where,
[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.
We are given:
[tex]V_1=156ml\\T_1=215^oC=(215+273)K=488K\\V_2=?\\T_2=550^0C=(550+273)K=823K[/tex]
Putting values in above equation, we get:
[tex]\frac{156}{488}=\frac{V_2}{823}\\\\V_2=263.09ml[/tex]
Thus final volume [tex]V_2[/tex] is 263.09 ml
Have scientists found any reliable predictors for earthquakes, like radon gas release or weird animal behavior?
Answer:
The "Parkfield earthquake prediction experiment" was the most heralded scientific earthquake prediction ever. It was based on an observation that the Parkfield segment of the San Andreas Fault breaks regularly with a moderate earthquake of about M 6 every several decades: 1857, 1881, 1901, 1922, 1934, and 1966.
Explanation:
this is the best I could come up with. luv u.
46g of a mineral contained 16g copper, 14g iron and 16g sulphur. Calculate the empirical
formula of the mineral.
Answer:
CuFeS2
Explanation:
Calculate the moles of each substance by doing moles= mass/relative atomic mass. you should get 0.25 moles of copper and iron and 0.5 moles of sulfur. Then divide all of those numbers by 0.25 (as its the lowest value) you should get 1 for copper and iron and 2 for sulfur. This represents the ratio that they are in within the mineral.
What is an oxidizing agent ?
Answer:
A substance that tends to bring about oxidation by being reduced and gaining electrons
Explanation:
Answer:
An oxidizing agent is a substance that takes negatively charged electrons "away" from a substance or object; usually taking these electrons for itself it can also transport the electrons from an object and "give" them to another substance or object. The object that has been oxidized will then have a positive charge after losing the negative electrons and the substance receiving the electrons will become negative.
Explanation:
Examples include halogens, potassium nitrate, and nitric acid.
CHEM HELP PLS 30 POINTS!!
1. what volume of 0.20 M HCl (aq) is needed to titrate 50 mL of 0.10 M NaOH to the endpoint?
A) 10.0 mL HCl
B) 40.0 mL HCl
C) 25.0 mL HCl
D) 20.0 mL HCl
2. what is the molarity of a NaOH solution if 40 mL of the solution is titrated to the endpoint with 15 mL of 1.50 M H2SO4?
A) 1.13 M
B) 1.47 M
C) 0.56 M
D) 0.75 M
3. suppose that 10.0 mL of HNO3 is neutralized by 71.4 mL of a 4.2 x 10 ^ -3 M solution of KOH in a titration. Calculate the concentration of the HNO3 solution.
A) 1.0 x 10 ^ -2 M
B) 3.0 x 10 ^ -2 M
C) 5.5 x 10 ^ -2 M
D) 1.0 x 10 ^ -14 M
Balanced equation
HCl + NaOH —> NaCl + H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nA) = 1The mole ratio of the base, NaOH (nB) = 1From the question given above, the following data were obtained:
Volume of base, NaOH (Vb) = 50 mLConcentration of base, NaOH (Cb) = 0.1 MConcentration of acid, HCl (Ca) = 0.2Volume of acid, HCl (Va) =?CaVa / CbVb = nA / nB
(0.2 × Va) / (0.1 × 50) = 1
(0.2 × Va / 5 = 1
Cross multiply
0.2 × Va = 5
Divide both side by 0.2
Va = 5 / 0.2
Va = 25 mL (Option C)
2. How to determine the molarity of NaOHBalanced equation
H₂SO₄+ 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1The mole ratio of the base, NaOH (nB) = 2From the question given above, the following data were obtained:
Volume of base, NaOH (Vb) = 40 mLConcentration of acid, H₂SO₄ (Ca) = 1.5 MVolume of acid, H₂SO₄ (Va) = 15 mL Concentration of base, NaOH (Cb) =?CaVa / CbVb = nA / nB
(1.5 × 15) / (Cb × 40) = 1 / 2
22.5 / (Cb × 40) = 1 / 2
Cross multiply
Cb × 40 = 22.5 × 2
Divide both side by 40
Cb = (22.5 × 2) / 40
Cb = 1.13 M (Option A)
3. How to determine the molarity of HNO₃Balanced equation
HNO₃ + KOH —> KNO₃ + H₂O
From the balanced equation above,
The mole ratio of the acid, HNO₃ (nA) = 1The mole ratio of the base, KOH (nB) = 1From the question given above, the following data were obtained:
Volume of base, KOH (Vb) = 71.4 mLConcentration of base, KOH (Cb) = 4.2×10¯³ MVolume of acid, HNO₃ (Va) = 10 mL Concentration of acid, HNO₃ (Ca) =?CaVa / CbVb = nA / nB
(Ca × 10) / (4.2×10¯³ × 71.4) = 1
(Ca × 10) / 0.29988 = 1
Cross multiply
Ca × 10 = 0.29988
Divide both side by 10
Ca = 0.29988 / 10
Ca = 3×10¯² M (Option B)
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If 7.0 mol sample of a gas has a volume of 12.2 L, what would the volume be if the amount of gas was increased to 16.8 mol
Answer:
[tex]V_{2} = 29.28\,L[/tex]
Explanation:
Let assume that gas behaves ideally and experiments an isobaric and isothermal processes. The following relationship is applied to determined the final volume:
[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}[/tex]
[tex]V_{2} = V_{1} \cdot \left(\frac{n_{2}}{n_{1}} \right)[/tex]
[tex]V_{2} = (12.2\,L)\cdot \left(\frac{16.8\,moles}{7\,moles} \right)[/tex]
[tex]V_{2} = 29.28\,L[/tex]
What is the formula of a potassium ion?
the answer is in the picture!
1. Calculate the molarity of 35g of calcium chloride (CaCl2) that is dissolved in 850ml of water. (Calculate moles first)
a. 0.27M
b. 0.38M
c. 0.32M
d. 0.80M
2. Calculate the molarity of 90g of copper sulfate (CuSO4) when dissolved in 5 L of water.
a. 0.112M
b. 2.8M
c. 0.56M
d. 0.50M
3. What is the molarity of NaOH if 0.70 moles are dissolved in 250 ml of water?
a. 175,000M
b. 2.8M
c. 0.175M
d. 4M
4. How many moles of Lithium oxide (Li20) are in 2 L of solution with a molarity of 2.0M?
a. 1 mole
b. 2 moles
c. 0.2 moles
d. 4 moles
5. How many moles of NaCl are in 7.5 L of 0.5M?
a. 3.75 moles
b. 15 moles
c. 0.066 moles
d. 2.5 moles
Answer:
yo I got same question do u know it
A sample of diborane gas has a pressure of 345 torr at a temperature of -15c and volume of 3.48L if conditions are changed so that the temperature is 36c and the pressure is 468 torr what will be the volume of the sample
Answer: 3.05L= V2
Explanation:
using
P1V1/T1=P2V2/T2
where p1= 345torr
T1, tempertaure= -15c+ 273=258K
T2, temperature= 36+ 273=309K
p2, Pressure= 468 torr
V2=???
P1V1/T1=P2V2/T2
v2=P1V1T2/T1P2= 345X3.46L X 309/ 258X 468=
V2= 3.05L
Give the molecular geometry and number of electron groups for sf4. give the molecular geometry and number of electron groups for . square planar, 6 electron groups square pyramidal, 6 electron groups t-shaped, 5 electron groups octahedral, 6 electron groups seesaw, 5 electron groups
Answer:
5 electron groups, see saw
Explanation:
During the formation of SF4, the sulfur atom usually bonds with each of four fluorine atoms where 8 of valence electrons are used. The four fluorine atoms have 3 lone pairs of electrons in its octet which will further utilize 24 valence electrons. In addition, two electrons are present as a lone pair on the sulfur atom. We can determine sulfur’s hybridization state by counting of the number of regions of electron density on sulphur (the central atom in the molecule). When bonding takes place there is a formation of 4 single bonds to sulfur and it has 1 lone pair. Looking at this, we can say that the number of regions of electron density is 5. The hybridization state is sp3d.
SF4 molecular geometry is seesaw with one pair of valence electrons. The molecule is polar. The equatorial fluorine atoms have 102° bond angles instead of the actual 120° angle. The axial fluorine atom angle is 173° instead of the actual 180° bond angle.
Ms. Clark is teaching her class about how plants make food for themselves. On the board, she has written this: __________ + air + water = food for plants
Answer:
sunlight
Explanation:
which substance increases in solubility as the temperature decreases
Answer:
Gas
hope this helped
