Answer:
IF the fruit juice contains a high level of vitamin C, THEN the preventative effectiveness against common cold increases.
Explanation:
The hypothesis is a testable explanation of a scientific investigation. It aims at predicting the outcome of the experiment. One feature of the hypothesis is that it must be testable. The hypothesis is usually written in an "IF, THEN" format.
This question is regarding an experiment to test the amount of vitamin C in fruit juice. The vitamin C is thought to be an effective preventative against common cold. Hence, the hypothesis connects the effect on common cold (dependent variable) with the amount of vitamin C (independent variable). The hypothesis can be written as:
IF the fruit juice contains a high level of vitamin C, THEN the preventative effectiveness against common cold increases.
<h3>
Answer:</h3>
0.643 moles
<h3>
Explanation:</h3>
We are given;
Density of nitrogen gas as 1.20 g/L
Volume nitrogen as 15.0 L
We are required to calculate the number moles of nitrogen gas;
<h3>Step 1: Determine the mass of nitrogen gas</h3>
We know the density is given by dividing mass by volume.
Therefore, to get the mass;
- Mass = Density × volume
- Mass = 1.20 g/L × 15.0 L
= 18 g
<h3>Step 2: Determine the mass of nitrogen gas </h3>
We know that to get the number of moles, we divide mass by molar mass;
That is, moles = Mass ÷ Molar mass
But, molar mass of nitrogen gas is 28 g/mol
Therefore;
Moles of nitrogen gas = 18 g ÷ 28 g/mol
= 0.643 moles
Therefore, the number of moles of nitrogen gas 0.643 moles
Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
Answer:
The pressure of a given amount of gas is directly proportional to its absolute temperature, provided that the volume does not change (Amontons's law). ... The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law).
In the compound Co2O3, cobalt has an oxidation number of 3, while oxygen's oxidation number is -2.
An oxidation number is a number assigned to an element in chemical combination that represents the number of electrons lost (or gained, if the number is negative) by an atom of that element in the compound.
