Heat required = Q = 40 kcal
Further explanationGiven
mass of 500 g ice
Required
Heat required
Solution
The heat to change the phase can be formulated :
Q = m.Lf (melting/freezing) Q = m.Lv (vaporization/condensation)Lf=latent heat of fusion
Lv=latent heat of vaporization
Lf for water = 334 kj/kg=6.01 kJ/mol = 80 cal/g
Phase change(ice to water)
Q= 500 g x 80 cal/g
Q = 40 kcal
what is ZnCl2 name and formula
Answer:
Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates
How many scientists have an element named after them?
75
35
5
15
Answer:
15
Explanation:
Answer: 15 people
Explanation:
Which of the following is physical change!?
a. dissolving
b. evaporating
c. bending
d. all of the above
To Become or cause to become incorporated into a liquid so as to form a solution.
Evaporation:The process of changing from liquid to vapour.
Bending:To shape or force something straight, in a curve or angle.
___________________________________
Which element requires the least amount of energy to remove the most loosely held electron?
Р
CI
Ar
Na
Which element requires the least amount of energy to remove the most loosely held electron?
aanswer: bromine
What happens to the stable atoms as the rocks get older?
A. increases
B. decreases
C. stay the same
Answer:
A
Explanation:
29. Which of the following is not a physical change?"
A) iron melting
B)food rotting
C)breaking a glass
D)shredding paper
Answer:
B food rotting
Explanation:
Food rotting is chemical change
Using the mass of baking soda that you used this lab, calculate the theoretical (expected) yield of NaCH3COO in grams ?
Mass of baking soda - 4.5 g
Answer:
4.4 g
Explanation:
The equation of the reaction is;
NaHCO3 (aq) + CH3COOH (aq) ----> CO2 (g) + H2O (l) + CH3COONa (aq)
Mass of baking soda - 4.5 g
Molar mass of NaHCO3 = 84.007 g/mol
Number of moles of baking soda= 4.5 g/84.007 g/mol = 0.0536 moles
If 1 mole of NaHCO3 yields 1 mole of CH3COONa
0.0536 moles of NaHCO3 also yields 0.0536 moles moles of CH3COONa
Hence;
Theoretical yield of CH3COONa = 0.0536 moles * 82.0343 g/mol = 4.4 g
How many liters are in 75.0 grams of nitrogen gas at STP?
Answer:
60 liter
Explanation:
mass =75 gm
no of mole =75/28
now volume = 22.4 * 75/28 =60
question: a group of similar organs doing the same job form the next step on the Ribbon of life which is
1. Connective tissue
2. An organ System
3. Nerve tissue
Answer:
the answer is An organ system
3 C₂ H₂
How many CzHg molecules are in the picture?
Answer:
i think it will 3 of each hope it helps. three molecules of each
What is the actual yield of a reaction?
Answer:
In chemistry, yield, also referred to as reaction yield, is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage
The actual yield of the reaction is the calculated amount of product. The correct option is C.
What is a yield?Yield is the final product that was produced after some labor. It might be a reaction, or we might grow something, and the result would be agricultural produce. In chemistry, the yield is related to the product that came after a chemical reaction.
In chemistry, there are two types of yields:
Theoretical yieldActual yield.The theoretical yield is the yield that we assumed, and the actual yield is the yield that actually comes after the reaction.
Thus, the correct option is C. The calculated amount of product.
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how the word triads coined in chemistry by johann dobereiner??
Answer:
In the history of the periodic table, Döbereiner's triads were an early attempt to sort the elements into some logical order by their physical properties. In 1817, a letter reported Johann Wolfgang Döbereiner's observations of the alkaline earths; namely, that strontium had properties that were intermediate to those of calcium and barium.[1] By 1829, Döbereiner had found other groups of three elements (hence "triads") whose physical properties were similarly related.[2] He also noted that some quantifiable properties of elements (e.g. atomic weight and density) in a triad followed a trend whereby the value of the middle element in the triad would be exactly or nearly predicted by taking the arithmetic mean of values for that property of the other two elements.
Which element is a metalloid? selenium (Se) germanium (Ge) phosphorus (P) iodine (I)
Answer:
Ge
Explanation:
Answer:germanium (Ge)
Explanation:
A metalloid is an chemical element that exhibit a mixture of both metals and non metals properties. On the periodic table, they can be found on a zig-zagging line going downwards from the boron to the astatine,dividing nonmetals on the right and the metals on the left. '
They include
boron (B) silicon (Si)germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At).Germanium is hard, has a grayish-white luster appearance and brittle that it can shatter like glass.
...
See related question here:https://brainly.com/question/18738298
Considering the activity series given for nonmetals, what is the result of the below reaction? Use the activity series provided. F > Cl > Br > I Br2 + NaF
Answer:
no reaction will occur.
Explanation:
The term ''activity series'' in chemistry is used to describe the series of metals and non metals arranged in an orderly manner of reactivity which is usually arranged from the most active elements to the least reactive elements.
So, from the question we are given that F > Cl > Br > I. This means that Fluorine, F is the most reactive element in this group of non metals[group seven in the periodic chart/table], while the least reactive element is the Iodine, I.
Hence, Cl, Br and I can not displace F in any chemical reaction since they are less reactive as compared to F.
Therefore, the reaction; Br2 + NaF will not occur because Bromine can not displace Fluorine. Fluorine is more reactive than Bromine
Answer:
A
Explanation:
EDGE
What is the total number of atoms in 3.0 molecules of propanone, CH3COCH3? (Avogadro’s constant = 6 x 1023 mol-1)
Answer:
1.81 x 10²⁴atoms
Explanation:
Given parameters:
Number of molecules = 3 moles
Unknown:
Number of atoms = ?
Solution:
To solve this problem, we are going to use the mole concept.
1 mole of any substance contains 6.02 x 10²³ atoms
So
3 mole of propanone will contain 3 x 6.02 x 10²³ atoms = 1.81 x 10²⁴atoms
The climate of an area is most affected by the amount of
A
animals in the region.
B
moonlight it receives.
C
people in the region.
D
sunlight it receives.
Answer:
D. I think
.........mm..
Why does barium have a larger atomic radius than beryllium!
Answer:
I think that it is related to the orbitals and the electron pairs in each atom.
try reading about "Vsepr" theory
Which of the following characteristics indicates that an atom is unstable?
A. A full valence shell
B. Forming very strong bonds
C. Existing by itself
D. Low electronegativity
Forming very strong bonds indicates that an atom is unstable. Option B
Characteristics of an unstable atomForces binding it are unbalancedThe nucleus possesses an excess internal energy.It lacks a full valence shell due to lack of electronsPossession of high electronegativity, due to attraction of electrons.Forms electrostatic bonds; very strong bonds.Therefore, forming very strong bonds indicates that an atom is unstable. Option B
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How does Gregor Mendel's work with pea plants affect human life today?
O A. People continue to cross pea plants to fix Mendel's many experimental mistakes.
B. People use Mendel's knowledge of DNA and chromosomes to create new species.
O C. People use the strains of pea plants that Mendel developed as a major food source.
D. People continue to selectively breed plants and animals to produce predictable results.
Answer:
D. People continue to selectively breed plants and animals to produce predictable results.
Explanation:
Gregor Mendel's work with pea plants affect human life today as a result of his ability to produce different results and genetic composition of pea plants through his crossing methods.
This laid the foundation for people today to continue to selectively breed plants and animals to produce predictable results which has lots of advantages associated with it.
1. (04.01 LC)
Which of the following is an example of how science can solve social problems? (5 po
It cathstop excessive rain from occurring.
It can identify the sources of polluted water.
It can control the time and day when cyclones happen.
It can reduce the frequency of severe weather conditions.
2. (04.01 LC)
Science is used to stop things the are incrediblu diffucult to deal with therefore jeg spiser ikke dreng
The answer is
It can identify the sources of polluted water.
How mariy molecules of water are in a 500.3 g sample?
Answer:
1.67×10^25 molecules
Explanation:
No of molecules = no of moles × Avogadros number
No of moles= mass in gram / molar mass
No of moles of water in given sample = 500.3/18
= 27.79 moles
No of molecules = 27.79× 6.02×10^ 23
= 167.32×10^23 or 1.67×10^25
18. What is the maximum temperature for holding cold, potentially hazardous food?
A. 32 degrees farenheit
B. 40 degrees farenheit
C. 41 degrees farenheit
D. 70 degrees farenheit
Answer: I believe the correct answer is C. 41 degrees Fahrenheit.
Explanation: Time and temperature are the most essential elements for monitoring the growth of disease-causing bacteria in food. The temperature danger zone lies between 40 degrees Farenheit and 140 degress Fahrenheit.
Hope this helps! ^^
Which particle model diagram represents only one compound composed of elements X and Z?
Key
= atom of element X
= atom of element z
A
B
С
D
Answer:c
Explanation:
why do particles in a matter vibrate/move?
Answer:
Explanation:
force
Answer:
energy!!
Explanation:
Guys help me pls
Which of type of elements are mainly gases at room temperature, dull and
brittle with low melting points?
3.50M solution? Show your work!
What is the molarity of these solutions? Show your work!
a. 3.5 mol HBr in 500 mL of water
b. 0.0750 mol NaCl in 250.0 mL of water
c. 1.95 mol AgNO3 in 1.2 L of water
d. 0.500 mol NH3 in 2.5 L of water
Answer:
a number is correct answer 9
2. Convert 1500 milligrams to grams.
Answer: 1.5 grams.
Explanation:
What is the speed of a helicopter at the traveled 1200 miles in 7 hours
Answer:
171
Explanation:
What is an example of a physical change that happens inside your body?
Helium is an unreactive gas and neon is a gas of extremely low reactivity.what if anything do their atom have in common?
Answer:
It belongs to the last group with all the gas whose last shell are common and they are unreactive unlike to other elements which reacts to complete there last shell with total 8 electrons . Helium and Neon have in common that they have there shell complete and they reacts very less or they don't.
Explanation:
Hope it is helpful....
