All categories

2 years ago

Calculate the concentration in % (m/m) of a solution containing 30.0g of mgcl2 dissolved in 270.0g of h20

1 answer:

4 0

As the question tells you, you need to use the formula

% mass= mass of solute/ mass of solution x 100

mass solute= 30.0 g
mass of solution= 30.0 + 270.0= 300.0 g

% mass= 30.0/ 300.0 x 100= 10%

answer is B

You might be interested in

Para que sirven los modelos atómicos

kolezko [41]

Answer:

mi no speak espanol

Explanation:

6 0

2 years ago

Write the atomic symbols for isotopes with the following characteristics? 1)an oxygen atom with 10 neutrons 2)a neon atom with t

VARVARA [1.3K]

Isotopes are elements that differ in the number in neutrons while the numner of protons are the same. The answers of the questions are: 1) 18/8 O 2) 22/10 Ne 3) 53/25 Mn 4) 37/24 Cr 5) 106/81 Ti.

8 0

3 years ago

A cubic piece of platinum metal (specific heat capacity = 0.1256 J/°C･g) at 200.0°C is dropped into 1.00 L of deuterium oxide ('

polet [3.4K]

Answer:

$a=5.65cm$

Explanation:

Hello,

In this case, for this heat transfer process in which the heat lost by the hot platinum is gained by the cold deuterium oxide based on the equation:

$Q_{Pt}=-Q_{Deu}$

We can represent the heats in terms of mass, heat capacities and temperatures:

$m_{Pt}Cp_{Pt}(T_f-T_{Pt})=-m_{Deu}Cp_{Deu}(T_f-T_{Deu})$

Thus, we solve for the mass of platinum:

$m_{Pt}=\frac{-m_{Deu}Cp_{Deu}(T_f-T_{Deu})}{Cp_{Pt}(T_f-T_{Pt})} \\\\m_{Pt}=\frac{-1.00L*1110g/L*4.211J/(g\°C)*(41.9-25.5)\°C}{0.1256J/(g\°C)*(41.9-200.0)\°C} \\\\m_{Pt}=3860.4g$

Next, by using the density of platinum we compute the volume:

$V_{Pt}=\frac{3860.4g}{21.45g/cm^3}\\ \\V_{Pt}=180cm^3$

Which computed in terms of the edge length is:

$V=a^3$

Therefore, the edge length turns out:

$a=\sqrt[3]{180cm^3}\\ \\a=5.65cm$

Best regards.

6 0

3 years ago

What is a substance's specific heat? the energy required to raise one kilogram of the substance one degree the energy required t

rodikova [14]

the energy required to raise one kilogram of the substance one degree

4 0

3 years ago

Which one of the following best represents the predicted approximate chemical shift and coupling for the hydrogen(s) indicated w

melomori [17]

Answer:

The answer is quartet 2.40 ppm.

Note: Kindly find an attached image below for the part of the solution to this question

Sources: The image was researched from Course hero platform

Explanation:

Solution

Multiplicity or (n+1) rule:

It helps in determination of multiplicity of an individual proton or individual types of proton which are available in the molecule.

Multiplicity =(n+1)

Thus

The non equivalent protons which are attached from adjacent atom is denoted by n.

Now because there are three non-equivalent protons are present at adjacent carbon of methylene group, hence the multiplicity of methylene hydrogen is given as follows:

The multiplicity will be the same for the two hydrogen's. thus we compute multiplicity only for one hydrogen atom stated below:

Non- equivalent = 3

Multiplicity = (3 +1)

= 4

= Quartet for 2H

A quartet for 2H indicates that the hydrogen atoms attached from the carbon, which is attached one side from a methyl group and the other side form an atom that have no any hydrogens.

Now due +I effect of carbonyl group, chemical shift value is high for these two hydrogens which is exactly at 2.40 ppm or 2.40 Quartet.

5 0

3 years ago