1. Which of the following is an SI base unit for time? (2 points)

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

7 0

3 years ago

there about 5000 elements, which combine to form the vast number of diffrent substances in the world around us

marissa [1.9K]

Answer: false 100

Explanation:

if this is the true or false test here

5 0

3 years ago

What would be the effect on this reaction of increasing the temperature?

Ainat [17]

Answer: D

Explanation: I got it wrong on my test :( and got this answer as correct.

6 0

2 years ago

Read 2 more answers

A 40.0-L sample of fluorine is heated from 90.0°C to 186.0°C. What volume will the sample occupy at the higher temperature?

jasenka [17]

Answer:

The volume will be 82.67 L

Explanation:

Charles's Law is the relationship between the volume and temperature of a certain amount of ideal gas. In this way, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio between volume and temperature will always have the same value:

$\frac{V}{T} = k$

Having a certain volume of gas V1 that is at a temperature T1 at the beginning of the experiment, by varying the volume of gas to a new value V2, then the temperature will change to T2, and it will be true:

$\frac{V1}{T1} =\frac{V2}{T2}$

In this case, you know:

V1= 40 L
T1= 90 °C
V2= ?
T2= 186 °C

Replacing:

$\frac{40L}{90C} =\frac{V2}{186 C}$

Solving:

$V2=\frac{40L}{90C} *186 C$

V2= 82.67 L

<u><em>The volume will be 82.67 L</em></u>

5 0

3 years ago

Find the length of time required for the total pressure in a system containing N2O5 at an initial pressure of 0.110 atm to rise

USPshnik [31]

Answer:

t = 37.1 s

Explanation:

The equation for the reaction is given as;

2 N2O5(g) --> 4 NO2 + O2

Initial: 0.110 - -

change: -2x +4x +x

Final: 0.110 - 2x +4x +x

But final = 0.150atm;

0.110 - 2x + 4x + x = 0.150 atm

3x = 0.150 - 0.110

x = 0.0133 atm

Pressure in reactant side;

0.110 - 2x

0.110 - 2 (0.0133) = 0.0834 atm

The integral rate law expression is given as;

ln ( [A] / [Ao] ) = -kt

k = rate constant = 7.48*10^-3*s-1

ln (0.0834/0.11) = (7.48*10^-3) t

upon solving, t = 37.1 s

3 0

3 years ago