Answer:
The percent by mass of water in this crystal is:
Explanation:
This exercise can be easily solved using a simple rule of three where the initial weight of the hydrated crystal (6,235 g) is taken into account as 100% of the mass, and the percentage to which the mass of 4.90 g corresponds (after getting warm). First, the values and unknown variable are established:
- 6,235 g = 100%
- 4.90 g = X
And the value of the variable X is found:
- X = (4.90 g * 100%) / 6,235 g
- X = approximately 78.6%.
The calculated value is not yet the percentage of the water, since the water after heating the glass has evaporated, therefore, the remaining percentage must be taken, which can be calculated by subtraction:
- Water percentage = Total percentage - Percentage after heating.
- <u>Water percentage = 100% - 78.6% = 21.4%</u>
The full question is shown in the image attached
Answer:
See explanation
Explanation:
In naming an alkane, the first thing we do is to obtain the parent chain by counting the number of carbon atoms in the chain.
When we obtain that, then we identify the substituents and number them in such a way that they have the lowest numbers. The compounds shown have the following names according to the order in which the structures appear in the image attached;
1. 2-methyl propane
2. 2,4-dimethyl heptane
3. 2,2,3,3-tetramethyl butane
4. 5-ethyl-2,4-dimethyl octane
There are many simple ways to prevent erosion. One of the simplest forms of preventing erosion is with vegetation and by establishing root systems that hold the soil together. You can also use geotextiles, fertilizers and also build retainer walls to keep the soil intact and prevent erosion.
Answer:
The answer is B
Explanation:
Less air means less air pressure. At a certain point, there is very little air pressure to push against the outward pressure of the helium inside the balloon. It will then expand until the rubber breaks, and the balloon bursts
Answer:
4chlorine;12thousand ;17zinc;2grams;three 8carbon;15aluminium
