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The temperature rises from 25.00°C to 29.00°C in a bomb calorimeter when 3.50 g of sucrose undergoes combustion in a bomb calori

julsineya [31]

Answer: Hence the energy change is -1918 kJ/mol

Given:

Initial temperature of calorimeter T1 = 25 C

Final temperature T2 = 29 C

Heat capacity of calorimeter c = 4.90 kJ/C

Mass of sucrose (m) = 3.5 g

Molar mass of sucrose (M) = 342.3 g/mol

To determine:

The energy change for the combustion of sucrose in kJ/mol

Explanation:

The change in temperature of calorimeter = T2 -T1 = 29 - 25 = 4 C

Heat gained by the calorimeter when the temperature changes by 4 C is-

= 4 C * 4.90 kJ/ 1 C = 19. 6 kJ

Now,

Heat gained by calorimeter = heat lost during combustion of 3.5 g sucrose = -19.6 kJ

# moles of sucrose = 3.5 g/342.3 g.mole-1 = 0.01022 moles

Energy change for the combustion reaction = -19.6/0.01022 = -1917.8 kJ/mol

8 0

3 years ago

A bullet of mass M1 is fired towards a block of mass m2 initially at rest at the edge of a frictionless table of height h as in

pantera1 [17]

The ratio of time of flight for inelastic collision to elastic collision is 1:2

The given parameters;

mass of the bullet, = m₁
mass of the block, = m₂
initial velocity of the bullet, = u₁
initial velocity of the block, = u₂

Considering inelastic collision, the final velocity of the system is calculated as;

$m_1u_1 + m_2u_2 = v(m_1 + m_2)\\\\m_1u_1 + 0 = v(m_1 + m_2)\\\\v= \frac{m_1u_1}{m_1 + m_2} \ -- (1)\\\\$

The time of motion of the system form top of the table is calculated as;

$v = u + gt\\\\v = 0 + gt\\\\v = gt\\\\t= \frac{v}{g} \\\\t_A = \frac{m_1u_1}{g(m_1 + m_2)} \ \ ---(2)$

Considering elastic collision, the final velocity of the system is calculated as;

$m_1u_1 + m_2 u_2 = m_1v_1 + m_2v_2\\\\m_1u_1 + 0 = m_1v_1 + m_2v_2\\\\m_1 u_1 = m_1v_1 + m_2v_2$

Apply one-directional velocity

$u_1 + (-v_1) = u_2 + v_2\\\\u_1 -v_1 = 0 + v_2\\\\v_1 = v_2 -u_1$

Substitute the value of $v_1$ into the above equation;

$m_1u_1 = m_1(v_2 - u_1) + m_2 v_2\\\\m_1u_1 = m_1v_2 -m_1u_1 + m_2v_2\\\\2m_1u_1 = m_1v_2 + m_2v_2\\\\2m_1u_1= v_2(m_1 + m_2)\\\\v_2 = \frac{2m_1u_1}{m_1+ m_2} \ --(3)$

where;

$v_2$ is the final velocity of the block after collision

Since the bullet bounces off, we assume that only the block fell to the ground from the table.

The time of motion of the block is calculated as follows;

$v_2 = v_0 + gt\\\\v_2 = 0 + gt\\\\t = \frac{v_2}{g} \\\\t_B = \frac{v_2}{g} \\\\ t_B = \frac{2m_1u_1}{g(m_1 + m_2)} \ \ ---(4)$

The ratio of time of flight for inelastic collision to elastic collision is calculated as follows;

$\frac{t_A}{t_B} = \frac{m_1u_1}{g(m_1 + m_2)} \times \frac{g(m_1 + m_2)}{2m_1u_1} \\\\\frac{t_A}{t_B} = \frac{1}{2} \\\\t_A:t_B = 1: 2$

Learn more about elastic and inelastic collision here: brainly.com/question/7694106

4 0

2 years ago

While wearing rubber-soled shoes, you rub a helium balloon on your sweater. The balloon becomes negative charged. Now release th

Sonja [21]

Answer: you are creatively creating static electricity.

Explanation:

6 0

3 years ago

What is the difference between Daniel and Leclanché cell

Thepotemich [5.8K]

Explanation:

Leclanche cell : Leclanche cell is also known as dry cells (fig 2). It contains an electrolyte of ammonium chloride. Carbon acts as a cathode while zinc is an anode.

Read more at Answer.Ya.Guru – https://answer.ya.guru/questions/959247-difference-between-daniel-and-leclanch-cells.htmlDaniel cells: It is a primary cell. It consists of a zinc rod and a copper vessel (in fig 1). It can be seen that a zinc rod is put in dilute sulfuric acid which is contained in a porous pot. Daniel cell works on the principle of the redox reaction. The electrons pass form zinc rod to wire. Then it passes to the copper rod. Thus, a current is produced.

Read more at Answer.Ya.Guru – https://answer.ya.guru/questions/959247-difference-between-daniel-and-leclanch-cells.html

3 0

2 years ago

When vibrational motion in an object increases, which is a true statement?

zubka84 [21]

A -..................................is the correct option

6 0

3 years ago

Read 2 more answers