Answer:
This question is incomplete and unclear; the complete question including the missing part is:
Emelie is working on a science project. Her task is to answer the question:
"Does Rogooti (a hair cream sold on TV) affect the speed of hair growth
(in length)". Her family is willing to volunteer for the experiment. Identify the control group (CG) and the independent and dependent variables.
ANSWER:
Independent variable: Rogooti hair cream
Dependent variable: Speed of hair growth/length
Control group: Family members that do not use the Rogooti hair cream
Explanation:
In an experiment, the independent variable is the variable that the experimenter changes or manipulates in order to bring about a measurable response. In this case, the ROGOOTI HAIR CREAM is the independent variable.
Dependent variable refers to the variable that is measured or the variable that responds to the change made to the independent variable. In this case, the dependent variable is SPEED AT WHICH HAIR GROWS (IN LENGTH).
Control group in an experiment is the group that does not receive the experimental treatment. In this case, the experimental treatment is the Rogooti hair cream, hence, the control group will be the VOLUNTEER FAMILY MEMBERS THAT DOES NOT RECEIVE THE ROGOOTI HAIR CREAM ON THEIR HAIR.
<span>The test dummy will continue forward until it makes contact with another object.</span>
Answer:
0.74 grams of methane
Explanation:
The balanced equation of the combustion reaction of methane with oxygen is:
it is clear that 1 mol of CH₄ reacts with 2 mol of O₂.
firstly, we need to calculate the number of moles of both
for CH₄:
number of moles = mass / molar mass = (3.00 g) / (16.00 g/mol) = 0.1875 mol.
for O₂:
number of moles = mass / molar mass = (9.00 g) / (32.00 g/mol) = 0.2812 mol.
- it is clear that O₂ is the limiting reactant and methane will leftover.
using cross multiplication
1 mol of CH₄ needs → 2 mol of O₂
??? mol of CH₄ needs → 0.2812 mol of O₂
∴ the number of mol of CH₄ needed = (0.2812 * 1) / 2 = 0.1406 mol
so 0.14 mol will react and the remaining CH₄
mol of CH₄ left over = 0.1875 -0.1406 = 0.0469 mol
now we convert moles into grams
mass of CH₄ left over = no. of mol of CH₄ left over * molar mass
= 0.0469 mol * 16 g/mol = 0.7504 g
So, the right choice is 0.74 grams of methane
Answer: The oxidation state of selenium in SeO3 is +6
Explanation:
SeO3 is the chemical formula for selenium trioxide.
- The oxidation state of SeO3 = 0 (since it is stable and with no charge)
- the oxidation number of oxygen (O) IN SeO3 is -2
- the oxidation state of selenium in SeO3 = Z (let unknown value be Z)
Hence, SeO3 = 0
Z + (-2 x 3) = 0
Z + (-6) = 0
Z - 6 = 0
Z = 0 + 6
Z = +6
Thus, the oxidation state of selenium in SeO3 is +6
In an equilibrium mixture of the three gases, PCO = PCl2 = 2.22 × 10-4 atm. The partial pressure of the product, phosgene (COCl2), is kp=(COCl2)/(CO)(Cl2) which is
. So, the correct answer is <span>A) 7.34.</span>
