Please help brainiest is award.

A sample of NaNo3 weighing 0.38g is placed in 50.0mL volumetric flask.The flask is then filled with water to the mark on the nec

snow_tiger [21]

Answer:

0.0894 M

Explanation:

So you first want to change the grams into moles (since molarity is moles solute per Liter solution).

The molar mass of NaNO3 is 84.995 g/mol, so we divide 0.38g of NaNO3 by 84.995 g/mol to get approximately 0.004471 mol NaNO3.

Now, all you have to do is to divide by the total Liters of water (your solution).

Since the volume is expressed in mL, you just need to divide by 1000 (1 L = 1000mL) to get 0.050 L solution.

Therefore, to get molarity, you divide 0.004471 mol by 0.050 L to get your answer of 0.0894 M.

5 0

3 years ago

When does the electron shown release the greatest amount of energy as it moves from one level to another?

ELEN [110]

S1 to GS as the amount of energy required to remove the electron is greatest when it is closest to the nucleus. think about two magents. does it take more energy to spereate them when they are far apart or when they are very close together? it's the same idea with electrons. the more energy required to remove, the more energy will be emmitted.

8 0

3 years ago

Predict the sign of the entropy change of the system for each of the following reactions.

storchak [24]

Answer :

(a) The entropy change will also decreases.

(b) The entropy change will also increases.

(c) The entropy change will also decreases.

(d) The entropy change will also increases.

Explanation :

Entropy : It is defined as the measurement of randomness or disorderedness in a system.

The order of entropy will be,

As we are moving from solid state to liquid state to gaseous state, the entropy will be increases due to the increase in the disorderedness.

As we are moving from gaseous state to liquid state to solid state, the entropy will be decreases due to the decrease in the disorderedness.

(a) $N_2(g)+3H_2(g)\rightarrow 2NH_3(g)$

In this reaction, the randomness of reactant molecules are more and as we move towards the formation of product the randomness become less that means the degree of disorderedness decreases. So, the entropy change will also decreases.

(b) $CaCO_3(s)\rightarrow CaO(s)+CO_2(g)$

In this reaction, the randomness of reactant molecules are less and as we move towards the formation of product the randomness become more that means the degree of disorderedness increase. So, the entropy change will also increases.

(c) $3C_2H_2(g)\rightarrow C_6H_6(g)$

In this reaction, 3 mole of gaseous $C_2H_2$ react to give 1 mole of gaseous $C_6H_6$ that means randomness become less that means the degree of disorderedness decreases. So, the entropy change will also decreases.

(d) $Al_2O_3(s)+3H_2(g)\rightarrow 2Al(s)+3H_2O(g)$

In this reaction, the number of moles of gases are same on both side of the reaction but 1 mole of solid $Al_2O_3$ react to give 2 moles of solid aluminium that means randomness become more that means the degree of disorderedness increases. So, the entropy change will also increases.

5 0

3 years ago

When a small amount of 12 M HNO3(aq) is added to a buffer solution made by mixing CH3NH2(aq) and CH3NH3Cl(aq) , the pH of the bu

fredd [130]

Answer:

a. CH3NH2(aq) + H⁺ → CH3NH3⁺

Explanation:

The mixture of a weak base as CH3NH2 with its conjugate acid CH3NH3Cl produce a buffer. As the weak acid is in equilibrium with water, the mixture of the weak base and its conjugate base produce that the acid or base released react avoiding the change in pH.

For example, when a strong acid as HNO3 reacts, the weak base will react producing the conjugate base, that is:

CH3NH2(aq) + H⁺ → CH3NH3⁺

Right answer is:

5 0

3 years ago

i'm reasking this, i need help with this and it's due today. the answer isn't 30,240 minutes, it's the blanks i need filled in :

adelina 88 [10]

Answer:

Explanation:

24hours ×21 days=

you will get the answeer

3 0

3 years ago