All categories

4 years ago

44. Convert the following. Express your answers in

Chemistry

1 answer:

professor190 [17]4 years ago

4 0

Answer:

A = 0.75 ×10² KJ.

B = 3.9 ×10³ dg

C = 0.22 × 10² μl.

Explanation:

A = 7.5 ×10⁴ j to kilo joules

7.5 ×10⁴ / 1000 = 0.75 ×10² KJ.

Joule is the smaller unit while kilo joule is the larger unit. One kilo joule equals to the thousand joule that's why we will divide the given value by 1000 in order to convert into KJ.

B = 3.9 ×10⁵ mg to decigrams.

3.9 ×10⁵ / 100 = 3.9 ×10³ dg

Decigram is larger unit while milligram is smaller unit. One decigram is equal to the 100 milligram. In order to convert the given value into decigram we have to divide the value by 100.

C = 2.21 ×10⁻⁴ dL to micorliters

2.21 ×10⁻⁴ ×10⁵ = 0.22 × 10² μl.

Deciliter is bigger unit then micro liter . One deciliter equals to the 100000 micro liters. In order to convert the dL into micro liter we have to multiply the given value with 100000.

You might be interested in

What is electronic configuration? What is the Law of Constant Composition?

Dovator [93]

Answer:

The law of constant proportions states that chemical compounds are made up of elements that are present in a fixed ratio by mass. This implies that any pure sample of a compound, no matter the source, will always consist of the same elements that are present in the same ratio by mass.

3 0

3 years ago

A student finds a rock on the way to school. In the laboratory he determines that the volume of the rock by placing the rock in

9966 [12]

Answer:

1.76 g/mL

Explanation:

You need to find the volume. You can do this by subtracting the volume of the water and the rock by the volume of the water.

72.7 mL - 50 mL = 22.7 mL

Now that you have volume, divide the mass by the volume to find the density.

39.943 g/22.7 mL = 1.76 g/mL

7 0

3 years ago

1. A sample of aluminum absorbs 50.1 J of heat, upon which the temperature of the sample increases from 20.0°C to 35.5°C. If the

Maurinko [17]

Answer:

Mass of aluminium in sample = 3.591 g ≅ 3.6 grams

Explanation:

Given that, A sample of aluminum absorbs 50.1 J of heat, upon which the temperature of the sample increases from 20.0°C to 35.5°C.

the specific heat of aluminum is 0.900 J/g- °C

The relation between heat absorbed and change in temperature is given by, Q = msΔT.

where Q = heat absorbed

m = mass of the substance

s = specific heat of substance

ΔT = change in temperature

Now, in our case, Q = 50.1 J ; s = 0.900 J/g- °C; ΔT= 35.5-20 = 15.5°C

⇒ m = $\frac{Q}{s(T_{2} -T_{1}) }$

⇒ m = $\frac{50.1}{0.900(15.5)}$ = 3.591 g ≅ 3.6 g

⇒ m ≅ 3.6 g

5 0

3 years ago

One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 8.00 liters against a constant external pressure

Leya [2.2K]

Answer : The work done on the surroundings is, 709.1 Joules.

Explanation :

The formula used for isothermally irreversible expansion is :

$w=-p_{ext}dV\\\\w=-p_{ext}(V_2-V_1)$

where,

w = work done

$p_{ext}$ = external pressure = 1.00 atm

$V_1$ = initial volume of gas = 1.00 L

$V_2$ = final volume of gas = 8.00 L

Now put all the given values in the above formula, we get :

$w=-p_{ext}(V_2-V_1)$

$w=-(1.00atm)\times (8.00-1.00)L$

$w=-7L.atm=-7\times 101.3J=-709.1J$

The work done by the system on the surroundings are, 709.1 Joules. In this, the negative sign indicates the work is done by the system on the surroundings.

Therefore, the work done on the surroundings is, 709.1 Joules.

4 0

3 years ago

explain how two substances can be at different temperatures but still have the same amount of thermal energy. give an example

Alex777 [14]

Two objects having the same internal energy may have different temperatures if their masses and specific heats are different and it's possible that an object with more eternal energy may be at a lower temperature than the one with less internal energy.

3 0

3 years ago