Answer: -
3.3° C
Explanation: -
Mass of water m = 180.5 g
Energy released as heat Q = 2494 J
Specific heat is defined as the heat required to raise the temperature of the unit mass of a given substance by 1 C.
Specific heat of water Cp = 4.184 (J/g)⋅∘C
Using the formula
Q = m x Cp x ΔT
We get temperature change ΔT = Q / (m x Cp)
= 2494 J / ( 180.5 g x 4.184 (J/g)⋅∘C
= 3.3° C
Thus the temprature change, (ΔT), of the wateris 3.3 °C if 180.5 g of water sat in the copper pipe from part A, releasing 2494 J of energy to the pipe
Answer:
Option c, Two atomic orbitals combine to form one molecular orbital
Explanation:
Molecular orbitals are formed by linear combination of atomic orbitals.
Some of the important facts of molecular orbital theories are as follows:
- No. of the molecular orbitals formed are equal to the no. of atomic orbitals participated.
- Half of the molecular orbitals are bonding molecular orbitals and half of the molecular orbitals are anti bonding molecular orbitals.
- Anti bonding molecular orbitals have energy higher than participating atomic orbitals.
- Bonding molecular orbitals have energy lower than participating atomic orbitals.
- Molecular orbitals are that region in the molecule where electrons are most likely to found.
So, among given, option c which is 'atomic orbitals combine to form one molecular orbital' is incorrect.
Answer:
A. In a graduated cylinder, put some quantity of water and measure the initial volume. Then put a coin and measure the volume. To find the volume of the coin, simply subtract the initial volume (water only) from the ending volume (water + coin). To measure the mass, take a dry coin and place it on an electronic scale. Density = mass / volume, so divide the mass by the volume to calculate the density of the coin.
B. When measuring the volume, make sure to look at the graduated cylinder at eye level and read from the bottom of the meniscus.
Answer:
![K_a=\frac{[H_3O^+][HCO_3^-]}{[H_2CO_3]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BHCO_3%5E-%5D%7D%7B%5BH_2CO_3%5D%7D)
Explanation:
Several rules should be followed to write any equilibrium expression properly. In the context of this problem, we're dealing with an aqueous equilibrium:
- an equilibrium constant is, first of all, a fraction;
- in the numerator of the fraction, we have a product of the concentrations of our products (right-hand side of the equation);
- in the denominator of the fraction, we have a product of the concentrations of our reactants (left-hand side o the equation);
- each concentration should be raised to the power of the coefficient in the balanced chemical equation;
- only aqueous species and gases are included in the equilibrium constant, solids and liquids are omitted.
Following the guidelines, we will omit liquid water and we will include all the other species in the constant. Each coefficient in the balanced equation is '1', so no powers required. Multiply the concentrations of the two products and divide by the concentration of carbonic acid:
The balanced equation for the reaction between NaOH and aspirin is as follows;
NaOH + C₉H₈O₄ --> C₉H₇O₄Na + H₂O
stoichiometry of NaOH to C₉H₈O₄ is 1:1
The number of NaOH moles reacted - 0.1002 M / 1000 mL/L x 10.00 mL
Number of NaOH moles - 0.001002 mol
Therefore number of moles of aspirin - 0.001002 mol
Mass of aspirin reacted - 0.001002 mol x 180.2 g/mol = 0.18 g
However the mass of the aspirin sample is 0.132 g but 0.18 g of aspirin has reacted, therefore this question is not correct.
