Can you help me with 2 and 3 please

A 0.1149-g sample of solid magnesium is burned in a bomb calorimeter that has a heat capacity of 1769 J/°C. The calorimeter cont

Andreas93 [3]

Answer:

The heat given off by the burning Mg is 30.5 kJ/grams or 745.5 kJ/mol

Explanation:

Step 1: Data given

Mass of magnesium sample = 0.1149 grams

Molar mass of magnesium = 24.3 g/mol

bomb calorimeter that has a heat capacity of 1769 J/°C

Mass of water = 321 grams

Temperature change = 1.126 °C

Step 2: Calculated heat released

Q = (1769 J/°C * 1.126 °C) + (321 grams * 4.184 J/g°C * 1.126 °C)

Q = 3504.18 J =3.504 kJ

Step 3: Calculate the heat given off by the burning Mg, in kJ/g

3.504 kJ / 0.1149 grams = 30.5 kJ/grams

Step 4: Calculate moles of Magnesium

Moles of magnesium = mass magnesium / Molar mass magnesium

Moles magnesium = 0.1149 grams / 24.3 g/mol

Moles magnesium = 0.0047 moles

Step 5: Calculate the heat given off by the burning Mg, in kJ/mol

3.504 kJ / 0.0047 moles = 745.5 kJ/mol

The heat given off by the burning Mg is 30.5 kJ/grams or 745.5 kJ/mol

8 0

3 years ago

Which focuses on the composition of matter

riadik2000 [5.3K]

There is no info for anyone to answer this

3 0

3 years ago

What type of claim must be supported by scientifically valid evidence for it to be approved for use on a food label? A. Health c

Lelu [443]

Option A. Health claim

Health claim must be supported by scientifically valid evidence to be approved in using for food label.

This is also a food guide to all consumers the food content implied by manufacturers to their products.

8 0

3 years ago

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state two methods that can be used to prepare chlorine from rock salt.write an equation in each case

Levart [38]

Answer:

electrolysis of brine

Explanation:

Rock salt deposits are usually mined; occasionally water is pumped down, and brine which contain 25 percent of sodium chloride is found

so d brine is electrolyzed to produce chlorine

7 0

2 years ago

Calculate the moles of calcium chloride (CaCl2) needed to react in order to produce 85.00 grams of calcium carbonate (CaCO3). us

BartSMP [9]

Answer:

0.85 mole

Explanation:

Step 1:

The balanced equation for the reaction of CaCl2 to produce CaCO3. This is illustrated below:

When CaCl2 react with Na2CO3, CaCO3 is produced according to the balanced equation:

CaCl2 + Na2CO3 -> CaCO3 + 2NaCl

Step 2:

Conversion of 85g of CaCO3 to mole. This is illustrated below:

Molar Mass of CaCO3 = 40 + 12 + (16x3) = 40 + 12 + 48 = 100g/mol

Mass of CaCO3 = 85g

Moles of CaCO3 =?

Number of mole = Mass /Molar Mass

Mole of CaCO3 = 85/100

Mole of caco= 0.85 mole

Step 3:

Determination of the number of mole of CaCl2 needed to produce 85g (i.e 0. 85 mole) of CaCO3.

This is illustrated below :

From the balanced equation above,

1 mole of CaCl2 reacted to produced 1 mole of CaCO3.

Therefore, 0.85 mole of CaCl2 will also react to produce 0.85 mole of CaCO3.

From the calculations made above, 0.85 mole of CaCl2 is needed to produce 85g of CaCO3

5 0

3 years ago

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