Answer:
b
Explanation:
As the coin is rubbed, the particles in the coin vibrate (presenting kinetic energy in the particles i.e. heat). The heat is transferred as thermal energy.
Answer: N = 2.78 × 10^23 atoms
There are N = 2.78 × 10^23 atoms in 70g of Au2cl6
Completed Question:
Calculate the number of gold atoms in a 70g sample of gold(III) chloride . Be sure your answer has a unit symbol if necessary, and round it to significant digits
Explanation:
Given:
Molar mass of Au2cl6 = 303.33g/mol
Mass of Au2cl6 = 70g
Number of moles of Au2cl6 = 70g/303.33g/mol = 0.231mol
According to the chemical formula of Au2cl6,
1 mole of Au2cl6 contains 2 moles of Au
Number of moles of Au = 2 × 0.231mol = 0.462mole
There are 6.022 × 10^23 atoms in 1 mole of an element.
Number of Atom of gold in 0.462 mole of gold is:
N = 0.462 mol × 6.022 × 10^23 atoms/mol
N = 2.78 × 10^23 atoms
Answer:
1.2 × 10² J
Explanation:
Given data
- Initial temperature: 295 K
The amount of heat (Q) that a substance absorbs depends on its specific heat capacity (c), which is the amount of heat energy required to raise the temperature of a substance per unit of mass. It can be calculated through the following expression. <em>(cFe = 0.444 J/g.K)</em>
![Q = c \times m \times (T_f-T_i) \\Q = \frac{0.444J}{g.K} \times 25g \times (306K-295K)\\Q = 1.2 \times 10^{2} J](https://tex.z-dn.net/?f=Q%20%3D%20c%20%5Ctimes%20m%20%5Ctimes%20%28T_f-T_i%29%20%5C%5CQ%20%3D%20%5Cfrac%7B0.444J%7D%7Bg.K%7D%20%20%5Ctimes%2025g%20%5Ctimes%20%28306K-295K%29%5C%5CQ%20%3D%201.2%20%5Ctimes%2010%5E%7B2%7D%20J)
Answer:
no
Explanation:
A compound is a material formed by chemically bonding two or more chemical elments.