Answer : The heat released by the eater is, [/tex]
Explanation :
Formula used :
or,
where,
Q = heat released = ?
m = mass of water = 200 g
c = specific heat of water =
= initial temperature =
= final temperature =
Now put all the given value in the above formula, we get:
[/tex]
Therefore, the heat released by the eater is, [/tex]
Answer:
0.342 mol
Explanation:
Molar mass of
NaCl = 58.4 g/mol
Number of moles in
20.0 g NaCl
is
20.0
g
58.4
g
/mol
=
0.342 mol
For the whole set of problems, always remember the Avogadro’s number is 6.023*10^23 units per mole of a substance. Units could be atoms, molecules or formula units.
The first question asks for the number of molecules of NaNO3. The molar mass of NaNO3 is 85 grams per mole. So,
150g NaNO3(1mole NaNO3/85 grams NaNO3)(6.023*10^23 molecules/1mole NaNO3)=1.063*10^24 molecules of NaNO3
5.7*10^46 molecules of NaNO3(1mole NaNO3/6.023*10^23 molecules)(85 grams NaNO3/1mole NaNO3) = 8.044*10^24 grams NaNO3
For the molar mass of water, we have 18.02grams per mole.
301 moles H2O(18.02 grams H2O/1 mole H2O) = 5424.02 grams H2O
For the molar mass of sulfuric acid, we have 98.08 grams per mole.
25g H2SO4(I mole H2SO4/98.08g H2SO4) = 0.2549 mole H2SO4
For the molar mass of Ca(OH)2, we have 74.1 grams per mole.
252gCa(OH)2(1mol/74.1g)(6.023*10^23/1mol) = 2.048*10^24 molecules of Ca(OH)2
For the molar mass of calcium, we have 40 grams of Ca per mole.
6.7*10^35 atoms Ca(1 mole Ca/6.023*10^23 atoms)(40g Ca/1mol Ca) = 4.45*10^13 grams Ca
Answer:
The mechanical energy of the system increases, provided there is no loss of energy due to friction. The energy would transform to kinetic energy when the speed is increasing. The mechanical energy of the system remains constant provided there is no loss of energy due to friction.
Explanation:
An object's mechanical energy generally increases as its velocity increases. This is because mechanical energy is the sum of an object's kinetic and potential energy, and kinetic energy is directly proportional to the square of its velocity.
In physics, mechanical energy is the energy that an object has due to its motion (kinetic energy) and position (potential energy). When an object's speed or velocity changes, specifically increases, so does its kinetic energy, as kinetic energy is directly proportional to the square of the object's velocity. Essentially, if an object's velocity doubles, its kinetic energy would quadruple. However, this does not take into account variables like air resistance, friction, or changes in potential energy. In an ideal, frictionless scenario, an increase in an object's velocity directly results in an increase in its mechanical energy.
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chromium, calcium, potassium
potassium, calcium, chromium
potassium, chromium, calcium
Answer: The correct order is:
Potassium > calcium > chromium
Explanation:
Potassium belongs to the group of alkali metals with group number 1 in a periodic table. Potassium easily displaces hydrogen atom from the water molecule.
Where as calcium belongs to group (II) and easily displaces hydrogen atom from the water molecule.
In a reactivity series potassium is comes before the calcium metal which means that it is more reactive than calcium metal.
Potassium > calcium
Where as chromium metal is member of group 6 and chromium reacts with steam and acids to form hydroxides. But doesn't reacts with water(in liquid phase) which means it less reactive then potassium and calcium.
Potassium > calcium > chromium
potassium, calcium, chromium