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3 years ago

PLS ANSWER FAST, WILL GIVE BRAINLIEST.

Chemistry

2 answers:

matrenka [14]3 years ago

7 0

Answer:

heat flows from warmer to colder objects

ololo11 [35]3 years ago

5 0

Answer:

(d) Heat flows from warmer to colder objects.

**wrong

answer is C

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Does this sound catchy or invite you to read more? "GMOs and pesticides are general amongst farmers for generations and should n

siniylev [52]

Answer:

It sounds fine, but it may be a bit too long. It's difficult to shorten things like this, but getting more straight to the point would give it that "catchy" feel.

Explanation:

3 0

3 years ago

A reaction of 41.9 g of Na and 30.3 g of Br2 yields 36.4 g of NaBr . What is the percent yield?

Licemer1 [7]

Answer: The percent yield is, 93.4%

Explanation:

First we have to calculate the moles of Na.

$\text{Moles of Na}=\frac{\text{Mass of Na}}{\text{Molar mass of Na}}=\frac{41.9g}{23g/mole}=1.82moles$

Now we have to calculate the moles of $Br_2$

${\text{Moles of}Br_2} = \frac{\text{Mass of }Br_2 }{\text{Molar mass of} Br_2} =\frac{30.3g}{160g/mole}=0.189moles$

${\text{Moles of } NaBr} = \frac{\text{Mass of } NaBr }{\text{Molar mass of } NaBr} =\frac{36.4g}{103g/mole}=0.353moles$

The balanced chemical reaction is,

$2Na(s)+Br_2(g)\rightarrow 2NaBr$

As, 1 mole of bromine react with = 2 moles of Sodium

So, 0.189 moles of bromine react with = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium

Thus bromine is the limiting reagent as it limits the formation of product and Na is the excess reagent.

As, 1 mole of bromine give = 2 moles of Sodium bromide

So, 0.189 moles of bromine give = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium bromide

Now we have to calculate the percent yield of reaction

$\%\text{ yield}=\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100=\frac{0.353 mol}{0.378}\times 100=93.4\%$

Therefore, the percent yield is, 93.4%

3 0

3 years ago

b)Elemental boron (as a gas) is produced in one industrial process by heating diboron trioxide with magnesium metal, also produc

dlinn [17]

<u>Answer:</u> The unbalanced chemical equation is written below.

<u>Explanation:</u>

Unbalanced chemical equation does not follow law of conservation of mass.

In an unbalanced chemical equation, total number of individual atoms on the reactant side will not be equal to the total number of individual atoms on the product side.

The chemical equation for the reaction of diboron trioxide and magnesium metal follows:

$B_2O_3(s)+Mg(s)\rightarrow B(g)+MgO(s)$

Hence, the unbalanced chemical equation is written above.

5 0

4 years ago

When a molecule of nad+ gains a hydrogen atom, the molecule becomes reduced.

Ilia_Sergeevich [38]

The answer is true.the molecule becomes reduced.

5 0

3 years ago

In the graph above for the dissociation of a strong acid, why do the bars for H3O+ and A- have the same height as the bar for HA

dimaraw [331]

Answer:

The concentration of HA is the same as concentration of H3O+ and A- produced.

Explanation:

The dissociation equation is given below:

HA(aq) + H2O (l) —> H3O+(aq) + A-(aq)

From the reaction above, we can see that the acid is monoprotic acid i.e it has only 1 ionisable hydrogen atom.

Now, from the balanced equation, we can see that the acid produced equal concentration of H3O+ and A-.

This account for the reason why the bars for H3O+ and A- have the same height as the bar for HA.

6 0

3 years ago