Answer:
K2 +Br ->2KBr
K + I ->KI
actually I don't know the e option but I had tried can u pls balance it urself
Answer: An example:
Measure the distance between the center of the spreading center (red) and the border between dark yellow and light green (65 Ma point) I measured 2 cm Since the scale on the map is 1 cm = 475 km, calculate the real distance that the plate has moved over the past 65 Ma 2 cm * 475 km/cm = 950 km = 95,000,000 cm = 9.5 * 107 cm Determine the length of time that the plate has been moving65 million years = 65,000,000 years = 6.5 * 107 yearsUse the above equation to calculate spreading rateR = d/t or R = 9.5 * 107 cm / 6.5 * 107 years = 1.46 cm/yr
Explanation:
The question has missing information, the complete question is:
Cobalt(II) chloride forms several hydrates with the general formula CoCl₂.xH₂O, where x is an integer. If the hydrate is heated, the water can be driven off, leaving pure CoCl₂ behind. Suppose a sample of a certain hydrate is heated until all the water is removed, and it's found that the mass of the sample decreases by 22.0%. Which hydrate is it? That is, what is x?
Answer:
CoCl₂.26H₂O
Explanation:
The molar masses of the compounds that forms the hydrate are:
Co = 59 g/mol
Cl = 35.5 g/mol
H = 1 g/mol
O = 16 g/mol
The molar mass of CoCl₂ is 130 g/mol and of H₂O is 18 g/mol, thus for the hydrate, it will be 130 + 18x g/mol.
Let's suppose 1 mol of the compound. Thus, the mass of the hydrate is: 130 + 18x, and the mass of CoCl₂ will be 130 g. Because the mass decreassed by 22.0% :
0.22*(130 + 18x) = 130
130 + 18x = 590.91
18x = 460.91
x ≅ 26
Thus, the hydrate is CoCl₂.26H₂O
Answer:
0.50 mol
Explanation:
The half-life is <em>the time required for the amount of a radioactive isotope to decay to half that amount</em>.
Initially, there are 8.0 moles.
- After 1 half-life, there remain 1/2 × 8.0 mol = 4.0 mol.
- After 2 half-lives, there remain 1/2 × 4.0 mol = 2.0 mol.
- After 3 half-lives, there remain 1/2 × 2.0 mol = 1.0 mol.
- After 4 half-lives, there remain 1/2 × 1.0 mol = 0.50 mol.
