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Heat required : Q = 83500 J = 83.5 kJ

Given

mass ice = 250 g at 0°C

Required

The heat required

Solution

The heat to change the phase can be formulated :

Q = m.Lf (melting/freezing)

Lf=latent heat of fusion

Input the value :

Q = 250 g x 334 J/g

Q = 83500 J

Answer:

13.25 ×10²³ atoms

Explanation:

Given data:

Mass of NaCl = 128 g

Number of atoms = ?

Solution:

First of all we will calculate the number of moles of NaCl.

Number of moles = mass/molar mass

Number of moles = 128 g/ 58.4 g/mol

Number of moles = 2.2 mol

Number of atoms:

1 mole of any substance contain 6.022×10²³ atoms.

2.2 mol × 6.022×10²³ atoms / 1mol

13.25 ×10²³ atoms

Answer:

Grams of chlorine gas to moles

The SI base unit for amount of substance is the mole. 1 grams Chlorine is equal to 0.028206357713029 mole.

Explanation:

Answer:

Hydrogen has three naturally occurringisotopes: 1H (protium), 2H (deuterium), and 3H (tritium). Other highly unstable nuclei (4H to 7H) have been synthesized in the laboratory, but do not occur in nature. The most stable radioisotope ofhydrogen is tritium, with a half-life of 12.32 years.

Answer:

Mn

Explanation: 4th shell so 4th row and count 7 from the left most column

Answer:

b. a meadow replacing a pond in it's flood plain

Explanation:

I'ts a secondary succession.

Answer:

Synthesis of Potassium Nitrate (KNO3)

When potassium hydroxide neutralizes nitric acid potassium nitrate is formed.

Answer:

Below.

Explanation:

Nitric acid and potassium hydroxide:

HNO3 + KOH  ---> KNO3 + H2O.

Answer:

Gas Pressure

Explanation:

Gas pressure is caused by the force exerted by gas molecules colliding with the surfaces of objects (Figure 5.2. 1). Although the force of each collision is very small, any surface of appreciable area experiences a large number of collisions in a short time, which can result in a high pressure.

Answer:

Collisions

Explanation:

It says that it was the answer.

Answer:

B

Explanation:

carbon 12 is most useful to humans

Answer:

3.98g

Explanation:

Given parameters:

Number of molecules = 1.2 x 10²⁴ molecules

Unknown:

Mass of H₂   = ?

Solution:

To find the mass of this molecule, we use the expression below:

    Mass  = number of moles x molar mass

Molar mass of H₂ = 2(1)  = 2g/mol

          6.02 x 10²³ molecules are contained in 1 mole of a substance

So;    1.2 x 10²⁴ molecules will  have [tex]\frac{1.2 x 10^{24} }{6.02 x 10^{23} }[/tex]    = 1.99 moles of H₂

Mass of H₂   = 1.99 x 2  = 3.98g

Answer:

+2

Explanation:

Ba is present in group 2 and group 2 show + oxidation state

Answer:

A

Explanation:

particles are frozen and hence will vibrate in their fixed positions

Answer:

Two cinder blocks 6 centimeters apart

Explanation:

im not 100% certain but the 2 cinder blocks are more dense than the other options

sry if its wrong

Answer:

s --- the round single circle

p --- the two lobes

d --- the four lobes

f --- complex shape

Answer:

V= L × W × H so the answer is 240,000

Answer:

The melting/boiling point of a substance determines what state of matter it takes at a certain temperature.

In Cl2 there are covalent bonds between the atoms forming simple molecules. There are weak attractions between molecules of Cl2 meaning little energy is needed to break these forces of attraction and therefore Cl2 has a low boiling point.

NaCl on the other hand has strong electrostatic forces of attraction between the positvely charged Na ion and the negatively charged Cl ion. NaCl forms a giant ionic lattice that requires high amounts of energy to break and therefore has a high melting point.

Answer: B

Explanation:

Answer: The kinetic energy of an object depends on both its mass and velocity, with its velocity playing a much greater role. Examples of Kinetic Energy: ... A baseball thrown by a pitcher, although having a small mass, can have a large amount of kinetic energy due to its fast velocity.

Explanation:

Hope this help

Answer:

Not balanced. There are different number of atoms on each side of equation.

Explanation:

Given balanced chemical equation:

Chemical equation:

3C₂H₄ + 3O₂    →       4CO₂ + 6H₂O

The equation is not balanced because  umber of moles of C, H and O are not balanced. It consist of six moles of C, 12 moles of H and six moles of oxygen on left side of equation while on right side there are 4 moles of C fourteen moles of oxygen and twelve moles of hydrogen present.

Balanced chemical equation:

C₂H₄ + 3O₂    →       2CO₂ + 2H₂O

Now the equation became balanced. There are two moles of carbon, four moles of hydrogen and six moles of oxygen are present on both side of equation.

Answer:

double displacement (metathesis) hope that helps!(^_^メ)

Explanation:

meh.

Answer:

ih2706

Explanation:

Answer:

According to Bohr, the amount of energy needed to move an electron from one zone to another is a fixed, finite amount. ... The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level. This situation is unstable, however.

Answer:   The final stage of the life cycle of a tree is when it has fully grown and reached the ... You should be confident in your supplier's approach to sustainability. ... This is the first occasion you will see a stem and perhaps a couple of leaves. ... The next phase is the sapling stage, this is when the sprout continues to grow and has ...

Explanation:

Answer:

reactants contain more energy in the decomposition reaction of sodium azide?

Explanation: