Can someone please help!

Lithium reacts more slowly with cold water than sodium.

guajiro [1.7K]

Answer:

1. Increase in the temperature of the water

2. Increasing the surface area of the lithium

Explanation:

1. Increase in the temperature of the water

The activation energy for the lithium water reaction is +161 kJ/mol while the activation energy for the sodium is +109 kJ/mol, hence for increased reaction rate, the water temperature will be raised to enable more lithium atoms enter into reaction with the water molecules as their energy is increased lowering the activation energy required for the reaction.

2. Increasing the surface area of the lithium

As the lithium floats on the water, due to its low temperature and the heat evolved from the reaction of lithium with the cold water is below the melting point of lithium, the reaction rate can be increased by increasing the surface area of lithium sample by grinding so as to increase the number of lithium water reaction sites.

3 0

3 years ago

Through the process of _______, materials move across a cell membrane from an area of higher concentration to an area of lower c

miskamm [114]

The answer is A. Remember that diffusion is the spontaneous process of solutes moving from areas of higher concentration to areas of lower concentration (spontaneous just means the process doesn't require an input of energy to occur).

4 0

3 years ago

Which is a strong base? HCl NaOH NH3 H3CO3

STatiana [176]

Answer:

The answer is B: NaOH :3

Explanation:

Hope this helped :D

6 0

3 years ago

1. Nuclear decay by alpha particle emission is more common in atoms of elements that:

11111nata11111 [884]

Answer 1) Option a) have an atomic number greater than 83

Explanation : Nuclear decay by alpha particle emission is more common in atoms of elements that have an atomic number greater than 83. Nuclear reactions occurs with the elements which have mass number more than 200.

Answer 2) Option D) $He^{4}_{2}$

Explanation : In the given nuclear reaction of helium;

$He^{3}_{2} + He^{3}_{2} ----->$ $He^{4}_{2} + 2 P^{1}_{1}$

Two helium isotopes combines to give another helium isotope with emission of a proton (P).

Answer 3) Option D) The products are more radioactive than the reactants.

Explanation : The major drawback of a nuclear fission reaction to be used as an reliable energy source is that it usually produces the products which are found to be more radioactive than the reactants.

Answer 4) Option D) All of the above concerns.

Explanation : Nuclear reactions are usually very harmful in nature. It raises many concerns about the waste disposal that is generated from the reaction. It also requires safe operation for the working nuclear plants. It can also be misused for nuclear weapon proliferation. Hence, the answer is all of the above.

Answer 5) False.

Explanation : The energy output of the Sun and other stars is a result of fusion reactions among hydrogen nuclei. In fusion reactions usually additions takes place.

Answer 6) Option B) The "missing" mass has been converted to energy

Explanation : The total mass of a helium nucleus not equal to the mass of its individual parts because the missing mass has to be converted into energy.

Answer 7) Option A) less than the mass-energy of the products

Explanation : In a nuclear reaction, the mass-energy of the reactants is generally less than that of the mass-energy of the products because some energy has to be generated while the reaction is progressing.

Answer 8) Option D) $9.00 X 10^{17} J$