Answer:
[tex]\boxed {\boxed {\sf 976.5 \ Joules}}[/tex]
Explanation:
We are asked to find the heat energy. Since we are given the mass, specific heat, and change in temperature, we should use this formula for heat:
[tex]q=mc\Delta T[/tex]
Where m is the mass, c is the specific heat, and ΔT is the change in temperature.
We know this is a 35.0 gram piece of wire, the temperature changes from 21 °C to 52°C and the specific heat is 0.900 J/ g °C.
Therefore,
m= 35.0 gc= 0.900 J/g °CΔT= 52 °C - 21°C= 31°CSubstitute these values into the formula.
[tex]q= (35.0 \ g)(0.900 \ J/g \ \textdegree C)(31 \textdegree C)[/tex]
Multiply the first two values. The grams will cancel each other out.
[tex]q=31.5 \ J/ \textdegree C (31 \textdegree C)[/tex]
Multiply again. This time, the degrees Celsius cancel each other out, so the final units are Joules.
[tex]q=976.5 \ J[/tex]
976.5 Joules of energy were required to heat the piece of metal.
What is TRUE about the majority of explosives that forensic scientists deal with in investigations?
А.
They are made of dynamite and TNT.
B.
They are Molotov cocktails.
C. They use high explosives.
D.
They are homemade bombs.
Answer:D
Explanation:
The majority of explosives that forensic scientists deal with in investigations are homemade bombs. Therefore, option D is correct.
What are forensic scientist ?In general, forensic scientists do the following kinds of work: They examine tangible materials gathered from crime sites. They offer forensic expert testimony both before and during court proceedings. Blood, hair, and other trace evidence are gathered by investigators and sent to crime labs for analysis.
Criminalists or crime scene investigators are generalist forensic science technicians that gather evidence at the scene of a crime and conduct scientific and technical examination in labs or offices.
A forensic scientist's key responsibilities include gathering evidence at the crime scene, documenting the findings in reports, processing the evidence at the lab, and giving testimony in court.
Thus, option D is correct.
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Compute the mass of KI needed to prepare 500 mL of a 0.750 M solution.
Answer:
62 grams
Explanation:
Molarity=mol/liter
We have mL and Molarity
500 mL * 1 L/1000 mL=0.5
Plug 0.5 in and solve for moles
0.75=mol/0.5
0.75*0.5=0.375 mol
Convert to grams by finding the mass of KI: 39+126.9= 165.9 grams
0.375 mol KI * 165.9 grams KI/1 mol KI= 62.2125 grams
The mass of KI needed is 124.5 grams, this can be calculated by adding the values in molarity formula.
What is Molarity?It is defined as number of moles of solute over volume of solution in liters.
It is given by:
M = n/ V
What information do we have?
Molarity= 0.750 M
Volume = 500 mL= 1 L
Molar mass of KI = 166 g/mol
To find:
Mass of KI=?
On substituting the values:
M= n/V
0.750 M= n/ 1 L
n= 0.750 M* 1l
n= 0.750 moles
Number of moles is the ratio between mass and molar mass.
n= m/M
0.750 moles = m/ 166 g/mol
m= 0.750*166
m= 124.5 grams.
Thus, the mass of KI needed is 124.5 grams.
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What is the fundamental different between combustion and nuclear reaction
Answer:
Nuclear reactions involve a change in an atom's nucleus, usually producing a different element. Chemical reactions, on the other hand, involve only a rearrangement of electrons and do not involve changes in the nuclear.
Addition of sugar to water will result in increase of boiling point
TRUE OR FALSE
Answer:
true
Explanation:
oi oi oi oi ewin
.................
What determines the degree of polarity in a bond?
Answer:
The relative electronegativity of the two bonded atoms determines the polarity of a bond. If the difference in electronegativities between the two atoms is less than 0.4, the bond is nonpolar covalent. ... If the difference in electronegativities between the two atoms is more than 2.0, the bond is ionic.
please answer asap!
What is the molarity of a KOH solution if 200 ml of the solution contains 0.6 moles KOH?
a. 0.3 M
b. 0.6 M
c. 3.0 M
d. 6.0 M
In another experiment, the student titrated 50.0 mL of 0.100 M HC,H,O, with
0.100 M NaOH(aq). Calculate the pH of the solution at the equivalence point
Answer:
Eqv Pt pH = 8.73
Explanation:
HOAc + NaOH => NaOAc + H₂O
50ml(0.10M HOAc) + 50ml(0.10M NaOH) => 100ml(0.05M NaOAc) + H₂O
For neutralized system, 100ml of 0.05M NaOAc remains
NaOAc => Na⁺ + OAc⁻
Na⁺ + H₂O => No Rxn
OAc⁻ + H₂O => HOAc + OH⁻
C(i) 0.05M ----- 0M 0M
ΔC -x ----- +x +x
C(f) 0.05-x
≅ 0.05M ----- x x
Kb = Kw/Ka = [HOAc][OH⁻]/[OAc⁻] = 1 X 10⁻¹⁴/1.7 X 10⁻⁵ = (x)(x)/(0.05M)
=> x = [OH⁻] = SqrRt(0.05 x 10⁻¹⁴/1.7 x 10⁻⁵) = 5.42 x 10⁻⁶M
=> pOH = -log[OH⁻] = -log(5.42 x 10⁻⁶) = 5.27
pH + pOH = 14 => pH = 14 - pOH = 14 - 5.27 = 8.73 Eqv Pt pH
Pls someone help me with this question pls
Why reaction between aqueous solutions of hydrochloric acid is commonly referred to as neutralization reaction?
Answer:
The chloride ion has no effect on the acidity of the solution since HCl is a strong acid. Chloride is a very weak base and will not accept a proton to a measurable extent. However, the ammonium ion, the conjugate acid of ammonia, reacts with water and increases the hydronium ion concentration:
Explanation:
Water is an essential molecule to life on Earth. Which of the following is not a property of water that is critical to biological life?
1. surface tension
2. density
3. temperature
4. viscosity
The property of water that is not critical to biological life is surface tension.
What is biological life?Biological life means the life in which living organism do exist and for their survival they mainly depends on water and air.
The main critical properties that water should posses to biological life are density, temperature, cohesive force and adhesive force. Viscosity is also understand by the cohesive force because more attraction between atoms more viscous they are.
Hence option (1) is correct i.e. surface tension.
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The diagram shows that the boiling point of water is 100°C At a pressure of one atm.
How could you reduce the boiling point of water in this system?
A. Increase the size of the flame
B. Decrease the volume of the water
C. Decrease the pressure to 0 atm.
D. Increase the pressure to 2 atm
Answer:
I think the answer will be number A
The boiling point of a substance is constant and for water it is 100 degree celsius. However by reducing the surrounding pressure the boiling point can be reduced.
What is boiling point ?Boiling point of a substances is the temperature at which the vapor pressure of the gas phase above the liquid equals to the atmospheric pressure where, the liquid converts to the vapor state.
Boiling point depends on the bond type, molar mass, temperature and pressure. As the and pressure increases, boiling point increases. Similarly with an increasing mass and more strength intermolecular force results in greater boiling point.
As the atmospheric pressure decreases, the temperature needed to equalise the vapor pressure of the gas phase over the liquid also decreases. Hence, boiling point decreases. Therefore, option C is correct.
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If the solubility of sodium chloride is 36 grams per 100 grams of water, which of the following solutions would be considered unsaturated? If the solubility of sodium chloride is 36 grams per 100 grams of water, which of the following solutions would be considered unsaturated? 3.25 moles of NaCl dissolved in 500 ml of water 1.85 moles of NaCl dissolved in 300 ml of water 5.8 moles of NaCl dissolved in 1 L of water none of the above
Answer: If the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.
Explanation:
A solution which contains the maximum amount of solute is called a saturated solution. Whereas a solution in which more amount of solute is able to dissolve is called an unsaturated solution.
Now, the number of moles present in 36 g of NaCl (molar mass = 58.4 g/mol) is as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{36 g}{58.4 g/mol}\\= 0.616 mol[/tex]
This shows that solubility of sodium chloride is 36 grams per 100 grams of water means a maximum of 0.616 mol of NaCl will dissolve in 100 mL of water.
So, a solution in which number of moles of NaCl are less than 0.616 mol per 100 mL then the solution formed will be an unsaturated solution.
As 5.8 moles of NaCl dissolved in 1 L (or 1000 mL) of water. So, moles present in 100 mL are calculated as follows.[tex]Moles = \frac{5.8 mol}{1000 mL} \times 100 mL\\= 0.58 mol[/tex]
Moles present in 100 mL of water for 3.25 moles of NaCl dissolved in 500 ml in water are as follows.[tex]Moles = \frac{3.25 mol}{500 mL} \times 100 mL\\0.65 mol[/tex]
Moles present in 100 mL of water for 1.85 moles of NaCl dissolved in 300 ml of water are as follows.[tex]Moles = \frac{1.85 mol}{300 mL} \times 100 mL\\= 0.616 mol[/tex]
Thus, we can conclude that if the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.
Question - Complete and balance the following chemical equations:
C8H18 + O2 --->
When you complete and balance the specific equation, give the following information:
State which type of chemical reaction this is.
Explain how you know which type of chemical reaction it is.
List the amount of each element you have when the equation is unbalanced. E.g. there is one mole of calcium on the reactants side.
Give the balanced chemical equation.
List the amount of each element you have when the equation is balanced.
The order of the elements that you balanced the equation with.
Explain how you know which coefficient to use for the specific compound.
Your Answer:
Answer:
2C8H18 + 25O2 -> 16CO2 + 18H2O
(16C, 36H, 50O)
H2O requires 2H per H2O, Meaning that you'd have 9H2O's from 1C8H18, but you still need that O2 for the CO2 and because the reactant side has 8C (within C8H18) You'd have to times the amount of required O2 from CO2 by 8. Even then you still don't have enough for both CO2 and H2O so you'll have to multiply MORE causing a bigger chain reaction resulting in 2C8H18 + 25O2 -> 16CO2 + 18H2O
Imagine the following scenario involving marbles as "radioactive isotopes".
Let's say the half-life of green marbles is 1 million years.
In one hand, you're holding 2 green marbles. In your other hand, you're holding 500,000 green marbles.
Hypothetically, noting that we have two different starting amounts of "isotopes", how long will it take for half of each amount to decay?
Answer:
1 million years
Explanation:
The half life of a radioactive isotope refers to the time it takes for the radioactive isotope to decay to half of its original amount.
The half life of a radioactive isotope is independent of the amount of starting material. Hence, whether the amount of starting material is small or large, the half life of the substance remains the same.
Hence the half life of 2 green marbles and 500,000 green marbles is 1 million years.
Your friend had an upset stomach caused by indigestion. His mother explained to him
that indigestion is when the contents in the stomach are too acidic. She also told him to
drink soda to settle his stomach. The soda did not help. You tell him that you would not
have expected the soda to help with the indigestion based on what you know about
acids and bases.
ليالي
Baking Soda
Acidic
Neutral
Basic
Explain why soda would not help settle your friend's stomach. In your reponse, be sure
to include:
• a better alternative to drinking soda.
• how each substance above would react with the stomach acid.
• defining characteristics of acids and bases, besides how they react.
Be sure to consider the completeness of your response, supporting details, and accurate
use of terms.
Answer:
because it may cause burn that causes acid to build up which causes you to keep having an upset stomach
What is the pH of an aqueous solution with a hydrogen ion concentration of [H+]=8.2×10 −7 M?
Answer:
6.1
Explanation:
From the question given above, the following data were obtained:
Hydrogen ion concentration [H⁺] = 8.2×10¯⁷ M
pH =?
The pH of the solution can be obtained as follow:
pH = –Log [H⁺]
pH = –Log 8.2×10¯⁷
pH = 6.1
Thus, the pH of the solution is 6.1
Why does the N2 molecule in this room have a greater average velocity
than the O2 molecules in the same room?
Answer:
Explanation:
The temperature will only move the average velocity of all the molecules in the room. There is a limitation. The O2 molecules are heavier than the N2 molecules. The lighter the molecules, the faster they are going to move on average.
1 Write the chemical symbols for following elements: Nitrogen-
Phosphorus- bromine- Zinc-Potassium-Magnesium.
Answer:
Look below
Explanation:
Nitrogen: N
Phosphorus: P
Bromine: Br
Zinc: Zn
Potassium: K
Magnesium: Mg
Hope this helps(would be very grateful if you mark this answer branliest bc i need for lvl up)
Pure gold has a density of 19.3 g/cm³. if it is made into a crown. what will be the density of the crown? how can you find out if the crown is indeed made of pure gold and nothing else?
Answer:
19.3g cm^3
If it deviates from the original 19.3g cm^3
An alkaline earth hydroxide, M(OH)2, was taken to lab for analysis. The unknown powder was poured into a flask and swirled in room temperature DI water until a saturated solution formed. This solution was then slowly filtered to remove the undissolved solid hydroxide. 28.5 mL of this saturated solution was titrated with 0.173 M HCl (aq). Endpoint required 25.10 mL of the HCl (aq) solution. Calculate the Ksp for this alkaline earth hydroxide.
Answer:
1.77 * 10^-3
Explanation:
From the titration formula;
Let
CA = concentration of acid
CB = concentration of base
VA = volume of acid
VB = volume of base
NA = number of moles of acid
NB = number of moles of base
The equation of the reaction is;
M(OH)2(aq) + 2HCl(aq) -------> MCl2(aq) + 2H2O(l)
So;
CAVA/CBVB= NA/NB
CAVANB = CBVBNA
CB= CAVANB/VBNA
CB= 0.173 * 25.10 * 1/28.5 * 2
CB= 4.3423/57
CB= 0.0762 M
This implies that the solubility of M(OH)2 = 0.0762 M
M(OH)2(s) ----> M^+(aq) + 2OH^-(aq)
So
Ksp = x * (2x)^2
Ksp = 4x^3
x = 0.0762
Ksp= 4(0.0762)^3
Ksp = 1.77 * 10^-3
Can someone please help me, i just need help =(
Answer:
The answers to your questions are given below
Explanation:
F. Determination of the missing part of the equation.
_ I₂ + _Na₂S₂O₃ —> _ NaI + _ Na₂S₄O₆
The above equation can be balance as illustrated below:
I₂ + Na₂S₂O₃ —> NaI + Na₂S₄O₆
There are 2 atoms of I on the left side and 1 on the right side. It can be balance by writing 2 before NaI as shown below:
I₂ + Na₂S₂O₃ —> 2NaI + Na₂S₄O₆
There are 2 atoms of Na on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before Na₂S₂O₃ as shown below:
I₂ + 2Na₂S₂O₃ —> 2NaI + Na₂S₄O₆
Now the equation is balanced.
The coefficients are: 1, 2, 2, 1
Elements >>> Reactant >>> Product
Sodium >>>>> 4 >>>>>>>>> 4
Sulphur >>>>> 4 >>>>>>>>> 4
Oxygen >>>>> 6 >>>>>>>>> 6
Iodine >>>>>> 2 >>>>>>>>>> 2
G. Determination of the missing part of the equation.
__ Mg + __P₄ —> __Mg₃P₂
The above equation can be balance as illustrated below:
Mg + P₄ —> Mg₃P₂
There are 2 atoms of P on the right side and 4 atoms on the left side. It can be balance by writing 2 before Mg₃P₂ as shown below:
Mg + P₄ —> 2Mg₃P₂
There are 6 atoms of Mg on the right side and 1 atom on the left side. It can be balance by writing 6 before Mg as shown below:
6Mg + P₄ —> 2Mg₃P₂
Now the equation is balanced.
The coefficients are: 6, 1, 2
Elements >>>> Reactant >>> Product
Magnesium >> 6 >>>>>>>>> 6
Phosphorus >> 4 >>>>>>>>> 4
What is an ionic solid?
Explanation:
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions.
An alternating current complete 100 cycles in 0.1s. it's frequency is
Answer:
The frequency is 1000 cycles/s
Explanation:
An alternating current is an electrical current in which the current changes its magnitude and the sense cyclically. The frequency of this current is defined as the cycles that the current completes in one second.
As the current completes 100 cycles in 0.1 seconds, the frequency is:
100 cycles / 0.1s = 1000 cycles /s
The frequency is 1000 cycles/sSteve and Meg are doing an experiment where they need to make 37 grams of Fe2O3. How many grams of Fe would they need ?
Answer:
25.9g
Explanation:
Molecular mass of Fe₂O₃ = (56 * 2) + (16 * 3)
= 112 + 48 = 160
Let's follow the unitary method now
In 160g Fe₂O₃ , there is 112 g Fe
In 1 g Fe₂O₃ , there is 112 / 160 g Fe
In 37 Fe₂O₃ , we need 112 * 37 / 160
= 25.9 g Fe
If you are given 96.0 grams of O2, how many grams of H20 are made?
Answer:
10.66 grams
Explanation:
keeping a bike indoor will stop it rusting true or false
Answer: True because if you leave it outside and it rains on the bike it will cause rust. Keep it in the garage or something. :) I have a bike btw.
Explanation:
The best way to prevent rusting is to store your bike safely away when it isn't being used and apply a rust-proofing lubricant to protect it when you are riding it – enjoying those wet and wild rides guilt-free!
so true
tiny sacs in the lungs where gas exchange takes place are called ____?
Answer:
Alveoli
Explanation:
I hope this helps you.
what is independent variable
Answer:
a variable (often denoted by x ) whose variation does not depend on that of another.
Explanation:
You can think of independent and dependent variables in terms of cause and effect: an independent variable is the variable you think is the cause, while a dependent variable is the effect. In an experiment, you manipulate the independent variable and measure the outcome in the dependent variable.For example, someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age.
help me plss plss.plsss.plsssplss plsss.plsss plsss plsss plsss
Answer:
1. Distance = 5 cm
Displacement = 1 cm
2. Distance = 7 cm
Displacement = 1 cm
3. Distance = 5 cm
Displacement = -1 cm
4. Distance = 6 cm
Displacement = -2 cm
5. Distance = 4 cm
Displacement = 0 cm
Explanation:
The distance an object travels is a measure of the total ground cobpvered bybthe object without regard to the direction of motion. It is a scalar quantity as it only takes into account magnitude but not the direction of a quantity.
Displacement however, is a measure of how far away or apart an object is from its starting position. It a vector quantity as it takes into account both the magnitude and direction in its measurement.
From the attachment provided, considering forward direction as positive and reverse as negative :
1. When a object moves from point 1 to point 4 and reverses to point 2.:
Distance = from 1 to 4 = 3 cm; from 4 back to 2 = 2 cm; 3 + 2 = 5 cm
Displacement = from 1 to 4 = +3 cm; from 4 back to 2 = -2 cm; 3 - 2 = 1 cm
2. When an object moves from point 1 to 5 and reverses to 2:
Distance = from 1 to 5 = 4cm; from 5 back to 2 = 3 cm; 4 + 3 = 7 cm
Displacement = from 1 to 5 = +4 cm; from 5 back to 2 = -4 cm; 4 - 3 = 1 cm
3. When an object moves from point 1 to 3 and then reverses to 0.
Distance = from 1 to 3 = 2 cm; from 3 back to 0 = 3 cm; 2 + 3 = 5 cm
Displacement = from 1 to 3 = +2 cm; from 3 back to 0 = -3 cm; 2 - 3 = -1 cm
4. When an object moves from point 3 to 5 and then reverses to 1:
Distance = from 3 to 5 = 2 cm; from 5 back to 1 = 4 cm; 2 + 4 = 6 cm
Displacement = from 3 to 5 = +2 cm; from 5 back to 1 = -4 cm; 2 - 4 = -2 cm
5. When an object moves from point 2 to 4 and then reverses to 3.
Distance = from 2 to 4 = 2 cm; from 4 back to 2 = 2 cm; 2 + 2 = 4 cm
Displacement = from 2 to 4 = +2 cm; from 4 back to 2 = -2 cm; 2 - 2 = 0 cm