beryllium & calcium are the two in the same column or family
Answer:
A. Yes, the substance must be water.
Explanation:
The density of a substance is unique to it. Density is defined the as the amount of substance contained per volume.
One of the ways of identifying a substance is to determine its density. Every matter is known to have their own specific densities. This makes them different from other substances. The density of gold is unique to it and it differs from that of silver.
In fact, water has density of 1.00gcm⁻³. Experimental errors and some little factors must have altered our expected figure. This a case of precision and accuracy in the experiment.
Answer: D. gravity
Explanation:
An airplane in flight is acted on by four forces: lift, the upward acting force; gravity, the downward acting force; thrust, the forward acting force; and drag, the backward acting force (also called wind resistance).
<span>6.50x10^3 calories.
Now we have 4 pieces of data and want a single result. The data is:
Mass: 100.0 g
Starting temperature: 25.0°C
Ending temperature: 31.5°C
Specific heat: 1.00 cal/(g*°C)
And we want a result with the unit "cal". Now you need to figure out what set of math operations will give you the desired result. Turns out this is quite simple. First, you need to remember that you can only add or subtract things that have the same units. You may multiply or divide data items with different units and the units can combine or cancel each other. So let's solve this:
Let's start with specific heat with the unit "cal/(g*°C)". The cal is what we want, but we'ld like to get rid of the "/(g*°C)" part. So let's multiply by the mass:
1.00 cal/(g*°C) * 100.0 g = 100.0 cal/°C
We now have a simpler unit of "cal/°C", so we're getting closer. Just need to cancel out the "/°C" part, which we can do with a multiplication. But we have 2 pieces of data using "°C". We can't multiply both of them, that would give us "cal*°C" which we don't want. But we need to use both pieces. And since we're interested in the temperature change, let's subtract them. So
31.5°C - 25.0°C = 6.5°C
So we have a 6.5°C change in temperature. Now let's multiply:
6.5°C * 100.0 cal/°C = 6500.0 cal
Since we only have 3 significant digits in our least precise piece of data, we need to round the result to 3 significant figures. 6500 only has 2 significant digits, and 6500. has 4. But we can use scientific notation to express the result as 6.50x10^3 which has the desired 3 digits of significance. So the result is 6.50x10^3 calories.
Just remember to pay attention to the units in the data you have. They will pretty much tell you exactly what to add, subtract, multiply, or divide.</span>
Answer:
Ksp = [Ca⁺²] × [C₂O₄⁻²]
Explanation:
Step 1: Write the balanced reaction for the dissociation of calcium oxalate
CaC₂O₄(s) ⇄ Ca⁺²(aq) + C₂O₄⁻²(aq)
Step 2: Write the expression for the solubility product constant (Ksp) of calcium oxalate
The solubility product constant is the equilibrium constant for the dissociation reaction, that is, it is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients. It doesn't include solids nor pure liquids because their activities are 1.
Ksp = [Ca⁺²] × [C₂O₄⁻²]
