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3 years ago

(a) 4.64 x 1024 atoms Bi into grams

Chemistry

1 answer:

nexus9112 [7]3 years ago

5 0

Answer:

1610.7 g is the weigh for 4.64×10²⁴ atoms of Bi

Explanation:

Let's do the required conversions:

1 mol of atoms has 6.02×10²³ atoms

Bi → 1 mol of bismuth weighs 208.98 grams

Let's do the rules of three:

6.02×10²³ atoms are the amount of 1 mol of Bi

4.64×10²⁴ atoms are contained in (4.64×10²⁴ . 1) /6.02×10²³ = 7.71 moles

1 mol of Bi weighs 208.98 g

7.71 moles of Bi must weigh (7.71 . 208.98 ) /1 = 1610.7 g

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In the following reaction, how many grams of NaBr will produce 244 grams of NaNO3? Pb(NO3)2(aq) 2 NaBr(aq) PbBr2(s) 2 NaNO3(aq)

lyudmila [28]

Answer : The mass of $NaBr$ is, 295.323 grams

Solution :

First we have to calculate the moles of $NaNO_3$ .

$\text{Moles of }NaNO_3=\frac{\text{Mass of }NaNO_3}{\text{Molar mass of }NaNO_3}=\frac{244g}{85g/mole}=2.87moles$

Now we have to calculate the moles of NaBr.

The balanced chemical reaction is,

$Pb(NO_3)_2(aq)+2NaBr(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)$

From the balanced reaction we conclude that

As, 2 moles of $NaNO_3$ react with 2 moles of $NaBr$

So, 2.87 moles of $NaNO_3$ react with 2.87 moles of $NaBr$

Now we have to calculate the mass of NaBr.

$\text{Mass of }NaBr=\text{Moles of }NaBr\times \text{Molar mass of }NaBr$

$\text{Mass of }NaBr=(2.87mole)\times (102.9g/mole)=295.323g$

Therefore, the mass mass of $NaBr$ is, 295.323 grams

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3 years ago

If all the water in 430.0 mL of a 0.45 M NaCI solution evaporates what is the mass of NaCI will remain

skad [1K]

Answer:

11.31 g.

Explanation:

Molarity is defined as the no. of moles of a solute per 1.0 L of the solution.

M = (no. of moles of solute)/(V of the solution (L)).

∴ M = (mass/molar mass)of NaCl/(V of the solution (L)).

∴ mass of NaCl remained after evaporation of water = (M)(V of the solution (L))(molar mass) = (0.45 M)(0.43 L)(58.44 g/mol) = 11.31 g.

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3 years ago

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the student records the concentration of the stock solution of H2O2 to be 0.950 M. The student proceeds to prepare the reaction

lana [24]

Answer:

0.0400M of KI

Explanation:

Molarity is an unit of concentration defined as the ratio between moles of solute and liters of solution.

When you add 10.0 mL of 0.10M KI and 15.0mL, total volume is:

25.0mL = 0.025L of solution

And moles of KI are:

0.0100L × 0.10M = 0.00100 moles of KI

Thus, molarity is:

0.00100 moles / 0.025L = 0.0400M of KI

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3 years ago

A student decomposed 3.67g of copper (ii) hydroxide into copper (ii) oxide. how many ml of 3m h2so4 is need to react with all th

vredina [299]

In the presence of heat, copper (II) hydroxide decomposes in to copper (II) oxide.
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What is the significant digit in 23.45

klio [65]

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