Which topic is Eunice's project most likely about?

If an element gives away an electron, will it form a positive ion or a negative<br> ion?

Elan Coil [88]

Answer:

posotive

Explanation:

electrons give off negative pulse so take one away

8 0

3 years ago

How many moles are in a 62.5-g sample of potassium nitrate (KNO3)?

Reil [10]

Answer:25.3 g of KNO₃ contain 0.25 moles.

Explanation:

7 0

2 years ago

What is heat transfer? Select one: O a. Thermal energy in transit due to spatial temperature difference o b. Thermal energy in t

IgorC [24]

Answer:

a. Thermal energy in transit due to spatial temperature difference .

Explanation:

Heat transfer -

Heat transfer is the exchange of the thermal energy or heat in between any physical systems .

It is the flow of energy or any form of energy from one system to another .

Heat transfer is divided into various mechanism , one of which is the thermal .

The thermal energy is the transit due to the spacial temperature difference .

6 0

2 years ago

The picture shows a contractile vacuole of a unicellular freshwater organism. The contractile vacuole regulates the flow of wate

yuradex [85]

Answer:

A.The concentration of water is greater outside the cell than inside the cell.

Explanation:

The contractile vacuole of certain organisms functions to regulate water flow in and out of the cell. It does this by storing excess water that comes into the cell. In the case of this organism with a filled up contractile vacuole, it means water is flowing into the cell.

Naturally, water will flow into a living cell when an osmotic gradient i.e. difference in concemtration, has been created between intracellular and extracellular solutions. Osmosis involves movement of substances from a region of high water concentration to a region of low water concentration. This means that if water is flowing into the cell, which is stored by the contractile vacuole, the concentration of water must be greater outside the cell than inside.

6 0

2 years ago

Hydrocyanic acid, HCN, is a weak acid. (a) Write the chemical equation for the dissociation of HCN in water. (b) Identify the Br

12345 [234]

Answer: a) $HCN(aq.)+H_2O\rightleftharoons H_3O^+(aq.)+CN^-(aq.)$

b) $HCN$ : acid $CN^-$ :conjugate base.

And, $H_2O$ : base $H_3O^+$ : conjugate acid.

c) $HCN(aq.)+NaOH(aq)\rightleftharoons NaCN(aq.)+H_2O(l)$

d) $NaCN(aq)\rightarrow Na^+(aq.)+CN^-(aq)$

e) $NaCN(aq)+HCl(aq)\rightarrow NaCl(aq.)+HCN(aq)$

Explanation:

a) Weak acid is defined as the acid which does not completely dissociates when dissolved in water. They have high pH. These releases $H^+$ ions in their aqueous states.

The equation for the dissociation of $HCN$ acid is given by:

$HCN(aq.)+H_2O\rightleftharoons H_3O^+(aq.)+CN^-(aq.)$

b) According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

For the given chemical equation:

$HCN$ is loosing a proton, thus it is considered as an acid and after losing a proton, it forms $CN^-$ which is a conjugate base.

And, $H_2O$ is gaining a proton, thus it is considered as a base and after gaining a proton, it forms $H_3O^+$ which is a conjugate acid.

c) Neutralization reaction is a reaction in which an acid reacts with base to produce salt and water.

$HCN(aq.)+NaOH(aq)\rightarrow NaCN(aq.)+H_2O(l)$

d) The chemical equation for dissociation of $NaCN$ in water.

$NaCN(aq)\rightarrow Na^+(aq.)+CN^-(aq)$

e) The chemical equation for the reaction of $NaCN$ and $HCI$

$NaCN(aq)+HCl(aq)\rightarrow NaCl(aq.)+HCN(aq)$

4 0

3 years ago