What is the isotope notation of the element that has an atomic number of 24 and a mass number of 52?

After completing an experiment to determine gravimetrically the percentage of water in a hydrate, a student reported a value of

zzz [600]

Answer:

A. Strong initial heating caused some of the hydrate sample to spatter out of the crucible.

Explanation:

Hi

The percentage of water in the sample is lower than expected.

A. Strong initial heating caused some of the hydrate sample to spatter out of the crucible:

If part of the sample is splashed from the crucible the mass of water detected will be less.

B. The dehydrated sample absorbed moisture after heating:

If the sample absorbs water after heating the percentage of water would be higher than expected.

C. The amount of the hydrate sample used was too small:

Depending on the sample size, different procedures can be chosen for analysis.

D. The crucible was not heated to constant mass before use:

In many occasions the crucible is heated next to the sample and not in previous form.

E. Excess heating caused the dehydration sample to decompose:

If the sample decomposes during heating, the analysis should be discarded.

success with your homework

4 0

3 years ago

A laboratory technician combined sodium hydroxide with excess iron(II) nitrate. A reaction took place according to this chemical

Whitepunk [10]

The initial mass of sodium hydroxide is 3.3 g (answer C)

<u><em>calculation</em></u>

Step 1 : find the moles of iron (ii) hydroxide ( Fe(OH)₂

moles = mass÷ molar mass

from periodic table the molar mass of Fe(OH)₂ = 56 + [16 +1]2 = 90 g/mol

moles is therefore = 3.70 g÷ 90 g/mol = 0.041 moles

Step 2: use the mole ratio to calculate the moles of sodium hydroxide (NaOH)

from given equation NaOH : Fe(OH)₂ is 2 :1

therefore the moles of NaOH = 0.041 x 2 = 0.082 moles

Step 3: find mass of NaOH

mass = moles x molar mass

from the periodic table the molar mass of NaOH = 23 +16 +1 = 40 g/mol

mass = 0.082 moles x 40 g/mol = 3.3 g ( answer C)

8 0

3 years ago

A sample of a compound contains 41.33 g of carbon and 8.67 g of hydrogen. The molar mass of the

mihalych1998 [28]

Answer:

C6H15

Explanation:

First, we calculate the empirical formula as follows:

C = 41.33 g

H = 8.67 g

We convert each mass value to mole by dividing each element by its molar mass (C = 12g/mol, H = 1g/mol)

C = 41.33g ÷ 12g/mol = 3.44mol

H = 8.67g ÷ 1g/mol = 8.67mol

Next, we divide each mole value by the smallest (3.44mol)

C = 3.44mol ÷ 3.44mol = 1

H = 8.67mol ÷ 3.44mol = 2.52

We multiply this ratio by 2 to get a simple whole number ratio

C = 1 × 2 = 2

H = 2.52 × 2 = 5.04

Based on this, the whole number ratio of C and H is 2:5, hence, the empirical formula is C2H5.

The molecular mass of the compound is given as 87.18 g/mol, hence, the molecular formula is calculated as follows:

(C2H5)n = 87.18

[12(2) + 1(5)]n = 87.18

[24 + 5]n = 87.18

(29)n = 87.18

n = 87.18 ÷ 29

n = 3.006

Approximately to whole number, n = 3

Hence, the molecular formula of the compound is [C2H5]3

= C6H15

4 0

2 years ago

Which of the following describes the greenhouse effect?

ankoles [38]

Earth's greenhouse gases trap heat in the atmosphere and warm the planet.

6 0

2 years ago

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Specific heat capacity is the quantity of heat required to raise the temperature of one mole of a substance by one degree Celsiu

sattari [20]

Answer

False

Explanation

Specific heat is the amount of heat per unit mass required to rise the temperature of a substance by one degree celsius.It is expressed in units of thermal energy per degree temperature.A calorimeter is used when measuring the heat capacity of a reaction.Molar heat capacity is amount of heat required to raise the temperature of a substance by one degree Celsius.

4 0

3 years ago

Read 2 more answers