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3 years ago

True or False: Water is a liquid at – 5 °C.

Chemistry

2 answers:

Lilit [14]3 years ago

8 0

Answer:

False

Explanation:

sveticcg [70]3 years ago

6 0

Answer:

False

Explanation:

Water's freezing point is at 0 degrees celsius

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Which of the below elements will not likely form an ionic bond?

Nookie1986 [14]

Answer:

Explanation:

I think this is right

3 0

3 years ago

Determine the theoretical yield of HCl if 60.0 g of BC13 and 37.5 g of H20 are reacted according to the following balanced react

Pie

Answer : The theoretical yield of HCl is, 56.1735 grams

Explanation : Given,

Mass of $BCl_3$ = 60 g

Mass of $H_2O$ = 37.5 g

Molar mass of $BCl_3$ = 117 g/mole

Molar mass of $H_2O$ = 18 g/mole

Molar mass of $HCl$ = 36.5 g/mole

First we have to calculate the moles of $BCl_3$ and $H_2O$ .

$\text{Moles of }BCl_3=\frac{\text{Mass of }BCl_3}{\text{Molar mass of }BCl_3}=\frac{60g}{117g/mole}=0.513moles$

$\text{Moles of }H_2O=\frac{\text{Mass of }H_2O}{\text{Molar mass of }H_2O}=\frac{37.5g}{18g/mole}=2.083moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$BCl_3(g)+3H_2O(l)\rightarrow H_3BO_3(s)+3HCl(g)$

From the balanced reaction we conclude that

As, 1 mole of $BCl_3$ react with 3 mole of $H_2O$

So, 0.513 moles of $BCl_3$ react with $3\times 0.513=1.539$ moles of $H_2O$

From this we conclude that, $H_2O$ is an excess reagent because the given moles are greater than the required moles and $BCl_3$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $HCl$ .

As, 1 mole of $BCl_3$ react to give 3 moles of $HCl$

So, 0.513 moles of $BCl_3$ react to give $3\times 0.513=1.539$ moles of $HCl$

Now we have to calculate the mass of $HCl$ .

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

$\text{Mass of }HCl=(1.539mole)\times (36.5g/mole)=56.1735g$

Therefore, the theoretical yield of HCl is, 56.1735 grams

7 0

3 years ago

Which type of energy is generated due to the movement of charged particles

masya89 [10]

Answer:

electrical energy

Explanation:

just took the test

3 0

3 years ago

Read 2 more answers

A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. H

Setler79 [48]

Problem One

Formula

N(t) = No * (1/2)^[t/t_1/2]

Givens

N(t) = the current mass of the sample = 2.10 grams

No = The original mass of the sample = No [We're trying to find this].

t = time elapsed which is 2.6 billion years or 2.6 * 10^9 years.

t1/2 = the 1/2 life time which is 1.3 billion years of 1.3 *10^9

Solution

2.10 grams = No (1/2)^(2.6*10^9/1.3 * 10^9)

The 10^9s cancel and you are left with 2.6/1.3 = 2

2.10 grams = No (1/2)^2

2.10 grams = No (1/4) Multiply both sides by 4

2.10 * 4 = No (1/4)*4

8.4 grams = No

which is how many grams you originally had.

Answer B.

Problem Two

$_{1}^{2}\text{H} + _{1}^{2}\text{H} \longrightarrow _{z}^{y}\text{x}+_{0}^{1}\text{n}$

Solve for y

2 + 2 = y + 1

4 = y + 1

y = 3

Solve for z

1 + 1 = z + 0

z = 2

The 2 tells you that it is the second member on the periodic table. That's Helium. So the answer looks like this.

$_{2}^{3}\text{He}$

The mass of the Helium is 3 and its number is two.

5 0

3 years ago

Help please help me

Alenkasestr [34]

Answer: It completely dissociates in water is a characteristic of strong acid.

Explanation:

An acid which dissociates completely to give hydrogen ions $(H^{+})$ is called a strong acid.

For example, HCl is a strong acid and it dissociates completely as follows.

$HCl \rightleftharpoons H^{+} + Cl^{-}$

Strong acids are able to conduct electricity in water as more number of ions are present in the solution as compared to the ions present in a solution of weak acid.

Strong acids increase the concentration of $H^{+}$ ions.

Thus, we can conclude that it completely dissociates in water is a characteristic of strong acid.

8 0

3 years ago